xref: /openbmc/linux/arch/s390/kernel/traps.c (revision 261a9af6)
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/lowcore.h>
43 #include <asm/debug.h>
44 #include "entry.h"
45 
46 pgm_check_handler_t *pgm_check_table[128];
47 
48 int show_unhandled_signals;
49 
50 extern pgm_check_handler_t do_protection_exception;
51 extern pgm_check_handler_t do_dat_exception;
52 extern pgm_check_handler_t do_asce_exception;
53 
54 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
55 
56 #ifndef CONFIG_64BIT
57 #define LONG "%08lx "
58 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
59 static int kstack_depth_to_print = 12;
60 #else /* CONFIG_64BIT */
61 #define LONG "%016lx "
62 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
63 static int kstack_depth_to_print = 20;
64 #endif /* CONFIG_64BIT */
65 
66 /*
67  * For show_trace we have tree different stack to consider:
68  *   - the panic stack which is used if the kernel stack has overflown
69  *   - the asynchronous interrupt stack (cpu related)
70  *   - the synchronous kernel stack (process related)
71  * The stack trace can start at any of the three stack and can potentially
72  * touch all of them. The order is: panic stack, async stack, sync stack.
73  */
74 static unsigned long
75 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
76 {
77 	struct stack_frame *sf;
78 	struct pt_regs *regs;
79 
80 	while (1) {
81 		sp = sp & PSW_ADDR_INSN;
82 		if (sp < low || sp > high - sizeof(*sf))
83 			return sp;
84 		sf = (struct stack_frame *) sp;
85 		printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
86 		print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
87 		/* Follow the backchain. */
88 		while (1) {
89 			low = sp;
90 			sp = sf->back_chain & PSW_ADDR_INSN;
91 			if (!sp)
92 				break;
93 			if (sp <= low || sp > high - sizeof(*sf))
94 				return sp;
95 			sf = (struct stack_frame *) sp;
96 			printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
97 			print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
98 		}
99 		/* Zero backchain detected, check for interrupt frame. */
100 		sp = (unsigned long) (sf + 1);
101 		if (sp <= low || sp > high - sizeof(*regs))
102 			return sp;
103 		regs = (struct pt_regs *) sp;
104 		printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
105 		print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
106 		low = sp;
107 		sp = regs->gprs[15];
108 	}
109 }
110 
111 static void show_trace(struct task_struct *task, unsigned long *stack)
112 {
113 	register unsigned long __r15 asm ("15");
114 	unsigned long sp;
115 
116 	sp = (unsigned long) stack;
117 	if (!sp)
118 		sp = task ? task->thread.ksp : __r15;
119 	printk("Call Trace:\n");
120 #ifdef CONFIG_CHECK_STACK
121 	sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
122 			  S390_lowcore.panic_stack);
123 #endif
124 	sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
125 			  S390_lowcore.async_stack);
126 	if (task)
127 		__show_trace(sp, (unsigned long) task_stack_page(task),
128 			     (unsigned long) task_stack_page(task) + THREAD_SIZE);
129 	else
130 		__show_trace(sp, S390_lowcore.thread_info,
131 			     S390_lowcore.thread_info + THREAD_SIZE);
132 	if (!task)
133 		task = current;
134 	debug_show_held_locks(task);
135 }
136 
137 void show_stack(struct task_struct *task, unsigned long *sp)
138 {
139 	register unsigned long * __r15 asm ("15");
140 	unsigned long *stack;
141 	int i;
142 
143 	if (!sp)
144 		stack = task ? (unsigned long *) task->thread.ksp : __r15;
145 	else
146 		stack = sp;
147 
148 	for (i = 0; i < kstack_depth_to_print; i++) {
149 		if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
150 			break;
151 		if (i && ((i * sizeof (long) % 32) == 0))
152 			printk("\n       ");
153 		printk(LONG, *stack++);
154 	}
155 	printk("\n");
156 	show_trace(task, sp);
157 }
158 
159 static void show_last_breaking_event(struct pt_regs *regs)
160 {
161 #ifdef CONFIG_64BIT
162 	printk("Last Breaking-Event-Address:\n");
163 	printk(" [<%016lx>] ", regs->args[0] & PSW_ADDR_INSN);
164 	print_symbol("%s\n", regs->args[0] & PSW_ADDR_INSN);
165 #endif
166 }
167 
168 /*
169  * The architecture-independent dump_stack generator
170  */
171 void dump_stack(void)
172 {
173 	printk("CPU: %d %s %s %.*s\n",
174 	       task_thread_info(current)->cpu, print_tainted(),
175 	       init_utsname()->release,
176 	       (int)strcspn(init_utsname()->version, " "),
177 	       init_utsname()->version);
178 	printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
179 	       current->comm, current->pid, current,
180 	       (void *) current->thread.ksp);
181 	show_stack(NULL, NULL);
182 }
183 EXPORT_SYMBOL(dump_stack);
184 
185 static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
186 {
187 	return (regs->psw.mask & bits) / ((~bits + 1) & bits);
188 }
189 
190 void show_registers(struct pt_regs *regs)
191 {
192 	char *mode;
193 
194 	mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
195 	printk("%s PSW : %p %p",
196 	       mode, (void *) regs->psw.mask,
197 	       (void *) regs->psw.addr);
198 	print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
199 	printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
200 	       "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
201 	       mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
202 	       mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
203 	       mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
204 	       mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
205 	       mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
206 #ifdef CONFIG_64BIT
207 	printk(" EA:%x", mask_bits(regs, PSW_BASE_BITS));
208 #endif
209 	printk("\n%s GPRS: " FOURLONG, mode,
210 	       regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
211 	printk("           " FOURLONG,
212 	       regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
213 	printk("           " FOURLONG,
214 	       regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
215 	printk("           " FOURLONG,
216 	       regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
217 
218 	show_code(regs);
219 }
220 
221 void show_regs(struct pt_regs *regs)
222 {
223 	print_modules();
224 	printk("CPU: %d %s %s %.*s\n",
225 	       task_thread_info(current)->cpu, print_tainted(),
226 	       init_utsname()->release,
227 	       (int)strcspn(init_utsname()->version, " "),
228 	       init_utsname()->version);
229 	printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
230 	       current->comm, current->pid, current,
231 	       (void *) current->thread.ksp);
232 	show_registers(regs);
233 	/* Show stack backtrace if pt_regs is from kernel mode */
234 	if (!(regs->psw.mask & PSW_MASK_PSTATE))
235 		show_trace(NULL, (unsigned long *) regs->gprs[15]);
236 	show_last_breaking_event(regs);
237 }
238 
239 static DEFINE_SPINLOCK(die_lock);
240 
241 void die(const char * str, struct pt_regs * regs, long err)
242 {
243 	static int die_counter;
244 
245 	oops_enter();
246 	debug_stop_all();
247 	console_verbose();
248 	spin_lock_irq(&die_lock);
249 	bust_spinlocks(1);
250 	printk("%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
251 #ifdef CONFIG_PREEMPT
252 	printk("PREEMPT ");
253 #endif
254 #ifdef CONFIG_SMP
255 	printk("SMP ");
256 #endif
257 #ifdef CONFIG_DEBUG_PAGEALLOC
258 	printk("DEBUG_PAGEALLOC");
259 #endif
260 	printk("\n");
261 	notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
262 	show_regs(regs);
263 	bust_spinlocks(0);
264 	add_taint(TAINT_DIE);
265 	spin_unlock_irq(&die_lock);
266 	if (in_interrupt())
267 		panic("Fatal exception in interrupt");
268 	if (panic_on_oops)
269 		panic("Fatal exception: panic_on_oops");
270 	oops_exit();
271 	do_exit(SIGSEGV);
272 }
273 
274 static void inline report_user_fault(struct pt_regs *regs, long int_code,
275 				     int signr)
276 {
277 	if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
278 		return;
279 	if (!unhandled_signal(current, signr))
280 		return;
281 	if (!printk_ratelimit())
282 		return;
283 	printk("User process fault: interruption code 0x%lX ", int_code);
284 	print_vma_addr("in ", regs->psw.addr & PSW_ADDR_INSN);
285 	printk("\n");
286 	show_regs(regs);
287 }
288 
289 int is_valid_bugaddr(unsigned long addr)
290 {
291 	return 1;
292 }
293 
294 static inline void __kprobes do_trap(long pgm_int_code, int signr, char *str,
295 				     struct pt_regs *regs, siginfo_t *info)
296 {
297 	if (notify_die(DIE_TRAP, str, regs, pgm_int_code,
298 		       pgm_int_code, signr) == NOTIFY_STOP)
299 		return;
300 
301         if (regs->psw.mask & PSW_MASK_PSTATE) {
302                 struct task_struct *tsk = current;
303 
304 		tsk->thread.trap_no = pgm_int_code & 0xffff;
305 		force_sig_info(signr, info, tsk);
306 		report_user_fault(regs, pgm_int_code, signr);
307         } else {
308                 const struct exception_table_entry *fixup;
309                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
310                 if (fixup)
311                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
312 		else {
313 			enum bug_trap_type btt;
314 
315 			btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
316 			if (btt == BUG_TRAP_TYPE_WARN)
317 				return;
318 			die(str, regs, pgm_int_code);
319 		}
320         }
321 }
322 
323 static inline void __user *get_psw_address(struct pt_regs *regs,
324 					   long pgm_int_code)
325 {
326 	return (void __user *)
327 		((regs->psw.addr - (pgm_int_code >> 16)) & PSW_ADDR_INSN);
328 }
329 
330 void __kprobes do_per_trap(struct pt_regs *regs)
331 {
332 	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
333 		return;
334 	if (tracehook_consider_fatal_signal(current, SIGTRAP))
335 		force_sig(SIGTRAP, current);
336 }
337 
338 static void default_trap_handler(struct pt_regs *regs, long pgm_int_code,
339 				 unsigned long trans_exc_code)
340 {
341         if (regs->psw.mask & PSW_MASK_PSTATE) {
342 		report_user_fault(regs, pgm_int_code, SIGSEGV);
343 		do_exit(SIGSEGV);
344 	} else
345 		die("Unknown program exception", regs, pgm_int_code);
346 }
347 
348 #define DO_ERROR_INFO(name, signr, sicode, str) \
349 static void name(struct pt_regs *regs, long pgm_int_code, \
350 		 unsigned long trans_exc_code) \
351 { \
352         siginfo_t info; \
353         info.si_signo = signr; \
354         info.si_errno = 0; \
355         info.si_code = sicode; \
356 	info.si_addr = get_psw_address(regs, pgm_int_code); \
357 	do_trap(pgm_int_code, signr, str, regs, &info);	    \
358 }
359 
360 DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
361 	      "addressing exception")
362 DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
363 	      "execute exception")
364 DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
365 	      "fixpoint divide exception")
366 DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
367 	      "fixpoint overflow exception")
368 DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
369 	      "HFP overflow exception")
370 DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
371 	      "HFP underflow exception")
372 DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
373 	      "HFP significance exception")
374 DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
375 	      "HFP divide exception")
376 DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
377 	      "HFP square root exception")
378 DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
379 	      "operand exception")
380 DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
381 	      "privileged operation")
382 DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
383 	      "special operation exception")
384 DO_ERROR_INFO(translation_exception, SIGILL, ILL_ILLOPN,
385 	      "translation exception")
386 
387 static inline void do_fp_trap(struct pt_regs *regs, void __user *location,
388 			      int fpc, long pgm_int_code)
389 {
390 	siginfo_t si;
391 
392 	si.si_signo = SIGFPE;
393 	si.si_errno = 0;
394 	si.si_addr = location;
395 	si.si_code = 0;
396 	/* FPC[2] is Data Exception Code */
397 	if ((fpc & 0x00000300) == 0) {
398 		/* bits 6 and 7 of DXC are 0 iff IEEE exception */
399 		if (fpc & 0x8000) /* invalid fp operation */
400 			si.si_code = FPE_FLTINV;
401 		else if (fpc & 0x4000) /* div by 0 */
402 			si.si_code = FPE_FLTDIV;
403 		else if (fpc & 0x2000) /* overflow */
404 			si.si_code = FPE_FLTOVF;
405 		else if (fpc & 0x1000) /* underflow */
406 			si.si_code = FPE_FLTUND;
407 		else if (fpc & 0x0800) /* inexact */
408 			si.si_code = FPE_FLTRES;
409 	}
410 	do_trap(pgm_int_code, SIGFPE,
411 		"floating point exception", regs, &si);
412 }
413 
414 static void __kprobes illegal_op(struct pt_regs *regs, long pgm_int_code,
415 				 unsigned long trans_exc_code)
416 {
417 	siginfo_t info;
418         __u8 opcode[6];
419 	__u16 __user *location;
420 	int signal = 0;
421 
422 	location = get_psw_address(regs, pgm_int_code);
423 
424 	if (regs->psw.mask & PSW_MASK_PSTATE) {
425 		if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
426 			return;
427 		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
428 			if (tracehook_consider_fatal_signal(current, SIGTRAP))
429 				force_sig(SIGTRAP, current);
430 			else
431 				signal = SIGILL;
432 #ifdef CONFIG_MATHEMU
433 		} else if (opcode[0] == 0xb3) {
434 			if (get_user(*((__u16 *) (opcode+2)), location+1))
435 				return;
436 			signal = math_emu_b3(opcode, regs);
437                 } else if (opcode[0] == 0xed) {
438 			if (get_user(*((__u32 *) (opcode+2)),
439 				     (__u32 __user *)(location+1)))
440 				return;
441 			signal = math_emu_ed(opcode, regs);
442 		} else if (*((__u16 *) opcode) == 0xb299) {
443 			if (get_user(*((__u16 *) (opcode+2)), location+1))
444 				return;
445 			signal = math_emu_srnm(opcode, regs);
446 		} else if (*((__u16 *) opcode) == 0xb29c) {
447 			if (get_user(*((__u16 *) (opcode+2)), location+1))
448 				return;
449 			signal = math_emu_stfpc(opcode, regs);
450 		} else if (*((__u16 *) opcode) == 0xb29d) {
451 			if (get_user(*((__u16 *) (opcode+2)), location+1))
452 				return;
453 			signal = math_emu_lfpc(opcode, regs);
454 #endif
455 		} else
456 			signal = SIGILL;
457 	} else {
458 		/*
459 		 * If we get an illegal op in kernel mode, send it through the
460 		 * kprobes notifier. If kprobes doesn't pick it up, SIGILL
461 		 */
462 		if (notify_die(DIE_BPT, "bpt", regs, pgm_int_code,
463 			       3, SIGTRAP) != NOTIFY_STOP)
464 			signal = SIGILL;
465 	}
466 
467 #ifdef CONFIG_MATHEMU
468         if (signal == SIGFPE)
469 		do_fp_trap(regs, location,
470 			   current->thread.fp_regs.fpc, pgm_int_code);
471         else if (signal == SIGSEGV) {
472 		info.si_signo = signal;
473 		info.si_errno = 0;
474 		info.si_code = SEGV_MAPERR;
475 		info.si_addr = (void __user *) location;
476 		do_trap(pgm_int_code, signal,
477 			"user address fault", regs, &info);
478 	} else
479 #endif
480         if (signal) {
481 		info.si_signo = signal;
482 		info.si_errno = 0;
483 		info.si_code = ILL_ILLOPC;
484 		info.si_addr = (void __user *) location;
485 		do_trap(pgm_int_code, signal,
486 			"illegal operation", regs, &info);
487 	}
488 }
489 
490 
491 #ifdef CONFIG_MATHEMU
492 asmlinkage void specification_exception(struct pt_regs *regs,
493 					long pgm_int_code,
494 					unsigned long trans_exc_code)
495 {
496         __u8 opcode[6];
497 	__u16 __user *location = NULL;
498 	int signal = 0;
499 
500 	location = (__u16 __user *) get_psw_address(regs, pgm_int_code);
501 
502         if (regs->psw.mask & PSW_MASK_PSTATE) {
503 		get_user(*((__u16 *) opcode), location);
504 		switch (opcode[0]) {
505 		case 0x28: /* LDR Rx,Ry   */
506 			signal = math_emu_ldr(opcode);
507 			break;
508 		case 0x38: /* LER Rx,Ry   */
509 			signal = math_emu_ler(opcode);
510 			break;
511 		case 0x60: /* STD R,D(X,B) */
512 			get_user(*((__u16 *) (opcode+2)), location+1);
513 			signal = math_emu_std(opcode, regs);
514 			break;
515 		case 0x68: /* LD R,D(X,B) */
516 			get_user(*((__u16 *) (opcode+2)), location+1);
517 			signal = math_emu_ld(opcode, regs);
518 			break;
519 		case 0x70: /* STE R,D(X,B) */
520 			get_user(*((__u16 *) (opcode+2)), location+1);
521 			signal = math_emu_ste(opcode, regs);
522 			break;
523 		case 0x78: /* LE R,D(X,B) */
524 			get_user(*((__u16 *) (opcode+2)), location+1);
525 			signal = math_emu_le(opcode, regs);
526 			break;
527 		default:
528 			signal = SIGILL;
529 			break;
530                 }
531         } else
532 		signal = SIGILL;
533 
534         if (signal == SIGFPE)
535 		do_fp_trap(regs, location,
536 			   current->thread.fp_regs.fpc, pgm_int_code);
537         else if (signal) {
538 		siginfo_t info;
539 		info.si_signo = signal;
540 		info.si_errno = 0;
541 		info.si_code = ILL_ILLOPN;
542 		info.si_addr = location;
543 		do_trap(pgm_int_code, signal,
544 			"specification exception", regs, &info);
545 	}
546 }
547 #else
548 DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
549 	      "specification exception");
550 #endif
551 
552 static void data_exception(struct pt_regs *regs, long pgm_int_code,
553 			   unsigned long trans_exc_code)
554 {
555 	__u16 __user *location;
556 	int signal = 0;
557 
558 	location = get_psw_address(regs, pgm_int_code);
559 
560 	if (MACHINE_HAS_IEEE)
561 		asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
562 
563 #ifdef CONFIG_MATHEMU
564         else if (regs->psw.mask & PSW_MASK_PSTATE) {
565         	__u8 opcode[6];
566 		get_user(*((__u16 *) opcode), location);
567 		switch (opcode[0]) {
568 		case 0x28: /* LDR Rx,Ry   */
569 			signal = math_emu_ldr(opcode);
570 			break;
571 		case 0x38: /* LER Rx,Ry   */
572 			signal = math_emu_ler(opcode);
573 			break;
574 		case 0x60: /* STD R,D(X,B) */
575 			get_user(*((__u16 *) (opcode+2)), location+1);
576 			signal = math_emu_std(opcode, regs);
577 			break;
578 		case 0x68: /* LD R,D(X,B) */
579 			get_user(*((__u16 *) (opcode+2)), location+1);
580 			signal = math_emu_ld(opcode, regs);
581 			break;
582 		case 0x70: /* STE R,D(X,B) */
583 			get_user(*((__u16 *) (opcode+2)), location+1);
584 			signal = math_emu_ste(opcode, regs);
585 			break;
586 		case 0x78: /* LE R,D(X,B) */
587 			get_user(*((__u16 *) (opcode+2)), location+1);
588 			signal = math_emu_le(opcode, regs);
589 			break;
590 		case 0xb3:
591 			get_user(*((__u16 *) (opcode+2)), location+1);
592 			signal = math_emu_b3(opcode, regs);
593 			break;
594                 case 0xed:
595 			get_user(*((__u32 *) (opcode+2)),
596 				 (__u32 __user *)(location+1));
597 			signal = math_emu_ed(opcode, regs);
598 			break;
599 	        case 0xb2:
600 			if (opcode[1] == 0x99) {
601 				get_user(*((__u16 *) (opcode+2)), location+1);
602 				signal = math_emu_srnm(opcode, regs);
603 			} else if (opcode[1] == 0x9c) {
604 				get_user(*((__u16 *) (opcode+2)), location+1);
605 				signal = math_emu_stfpc(opcode, regs);
606 			} else if (opcode[1] == 0x9d) {
607 				get_user(*((__u16 *) (opcode+2)), location+1);
608 				signal = math_emu_lfpc(opcode, regs);
609 			} else
610 				signal = SIGILL;
611 			break;
612 		default:
613 			signal = SIGILL;
614 			break;
615                 }
616         }
617 #endif
618 	if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
619 		signal = SIGFPE;
620 	else
621 		signal = SIGILL;
622         if (signal == SIGFPE)
623 		do_fp_trap(regs, location,
624 			   current->thread.fp_regs.fpc, pgm_int_code);
625         else if (signal) {
626 		siginfo_t info;
627 		info.si_signo = signal;
628 		info.si_errno = 0;
629 		info.si_code = ILL_ILLOPN;
630 		info.si_addr = location;
631 		do_trap(pgm_int_code, signal, "data exception", regs, &info);
632 	}
633 }
634 
635 static void space_switch_exception(struct pt_regs *regs, long pgm_int_code,
636 				   unsigned long trans_exc_code)
637 {
638         siginfo_t info;
639 
640 	/* Set user psw back to home space mode. */
641 	if (regs->psw.mask & PSW_MASK_PSTATE)
642 		regs->psw.mask |= PSW_ASC_HOME;
643 	/* Send SIGILL. */
644         info.si_signo = SIGILL;
645         info.si_errno = 0;
646         info.si_code = ILL_PRVOPC;
647 	info.si_addr = get_psw_address(regs, pgm_int_code);
648 	do_trap(pgm_int_code, SIGILL, "space switch event", regs, &info);
649 }
650 
651 asmlinkage void __kprobes kernel_stack_overflow(struct pt_regs * regs)
652 {
653 	bust_spinlocks(1);
654 	printk("Kernel stack overflow.\n");
655 	show_regs(regs);
656 	bust_spinlocks(0);
657 	panic("Corrupt kernel stack, can't continue.");
658 }
659 
660 /* init is done in lowcore.S and head.S */
661 
662 void __init trap_init(void)
663 {
664         int i;
665 
666         for (i = 0; i < 128; i++)
667           pgm_check_table[i] = &default_trap_handler;
668         pgm_check_table[1] = &illegal_op;
669         pgm_check_table[2] = &privileged_op;
670         pgm_check_table[3] = &execute_exception;
671         pgm_check_table[4] = &do_protection_exception;
672         pgm_check_table[5] = &addressing_exception;
673         pgm_check_table[6] = &specification_exception;
674         pgm_check_table[7] = &data_exception;
675         pgm_check_table[8] = &overflow_exception;
676         pgm_check_table[9] = &divide_exception;
677         pgm_check_table[0x0A] = &overflow_exception;
678         pgm_check_table[0x0B] = &divide_exception;
679         pgm_check_table[0x0C] = &hfp_overflow_exception;
680         pgm_check_table[0x0D] = &hfp_underflow_exception;
681         pgm_check_table[0x0E] = &hfp_significance_exception;
682         pgm_check_table[0x0F] = &hfp_divide_exception;
683         pgm_check_table[0x10] = &do_dat_exception;
684         pgm_check_table[0x11] = &do_dat_exception;
685         pgm_check_table[0x12] = &translation_exception;
686         pgm_check_table[0x13] = &special_op_exception;
687 #ifdef CONFIG_64BIT
688 	pgm_check_table[0x38] = &do_asce_exception;
689 	pgm_check_table[0x39] = &do_dat_exception;
690 	pgm_check_table[0x3A] = &do_dat_exception;
691         pgm_check_table[0x3B] = &do_dat_exception;
692 #endif /* CONFIG_64BIT */
693         pgm_check_table[0x15] = &operand_exception;
694         pgm_check_table[0x1C] = &space_switch_exception;
695         pgm_check_table[0x1D] = &hfp_sqrt_exception;
696 	/* Enable machine checks early. */
697 	local_mcck_enable();
698 }
699