xref: /openbmc/linux/arch/s390/kernel/traps.c (revision 615c36f5)
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 <linux/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 void (*pgm_check_table[128])(struct pt_regs *, long, unsigned long);
47 
48 int show_unhandled_signals;
49 
50 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
51 
52 #ifndef CONFIG_64BIT
53 #define LONG "%08lx "
54 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
55 static int kstack_depth_to_print = 12;
56 #else /* CONFIG_64BIT */
57 #define LONG "%016lx "
58 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
59 static int kstack_depth_to_print = 20;
60 #endif /* CONFIG_64BIT */
61 
62 /*
63  * For show_trace we have tree different stack to consider:
64  *   - the panic stack which is used if the kernel stack has overflown
65  *   - the asynchronous interrupt stack (cpu related)
66  *   - the synchronous kernel stack (process related)
67  * The stack trace can start at any of the three stack and can potentially
68  * touch all of them. The order is: panic stack, async stack, sync stack.
69  */
70 static unsigned long
71 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
72 {
73 	struct stack_frame *sf;
74 	struct pt_regs *regs;
75 
76 	while (1) {
77 		sp = sp & PSW_ADDR_INSN;
78 		if (sp < low || sp > high - sizeof(*sf))
79 			return sp;
80 		sf = (struct stack_frame *) sp;
81 		printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
82 		print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
83 		/* Follow the backchain. */
84 		while (1) {
85 			low = sp;
86 			sp = sf->back_chain & PSW_ADDR_INSN;
87 			if (!sp)
88 				break;
89 			if (sp <= low || sp > high - sizeof(*sf))
90 				return sp;
91 			sf = (struct stack_frame *) sp;
92 			printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
93 			print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
94 		}
95 		/* Zero backchain detected, check for interrupt frame. */
96 		sp = (unsigned long) (sf + 1);
97 		if (sp <= low || sp > high - sizeof(*regs))
98 			return sp;
99 		regs = (struct pt_regs *) sp;
100 		printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
101 		print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
102 		low = sp;
103 		sp = regs->gprs[15];
104 	}
105 }
106 
107 static void show_trace(struct task_struct *task, unsigned long *stack)
108 {
109 	register unsigned long __r15 asm ("15");
110 	unsigned long sp;
111 
112 	sp = (unsigned long) stack;
113 	if (!sp)
114 		sp = task ? task->thread.ksp : __r15;
115 	printk("Call Trace:\n");
116 #ifdef CONFIG_CHECK_STACK
117 	sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
118 			  S390_lowcore.panic_stack);
119 #endif
120 	sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
121 			  S390_lowcore.async_stack);
122 	if (task)
123 		__show_trace(sp, (unsigned long) task_stack_page(task),
124 			     (unsigned long) task_stack_page(task) + THREAD_SIZE);
125 	else
126 		__show_trace(sp, S390_lowcore.thread_info,
127 			     S390_lowcore.thread_info + THREAD_SIZE);
128 	if (!task)
129 		task = current;
130 	debug_show_held_locks(task);
131 }
132 
133 void show_stack(struct task_struct *task, unsigned long *sp)
134 {
135 	register unsigned long * __r15 asm ("15");
136 	unsigned long *stack;
137 	int i;
138 
139 	if (!sp)
140 		stack = task ? (unsigned long *) task->thread.ksp : __r15;
141 	else
142 		stack = sp;
143 
144 	for (i = 0; i < kstack_depth_to_print; i++) {
145 		if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
146 			break;
147 		if (i && ((i * sizeof (long) % 32) == 0))
148 			printk("\n       ");
149 		printk(LONG, *stack++);
150 	}
151 	printk("\n");
152 	show_trace(task, sp);
153 }
154 
155 static void show_last_breaking_event(struct pt_regs *regs)
156 {
157 #ifdef CONFIG_64BIT
158 	printk("Last Breaking-Event-Address:\n");
159 	printk(" [<%016lx>] ", regs->args[0] & PSW_ADDR_INSN);
160 	print_symbol("%s\n", regs->args[0] & PSW_ADDR_INSN);
161 #endif
162 }
163 
164 /*
165  * The architecture-independent dump_stack generator
166  */
167 void dump_stack(void)
168 {
169 	printk("CPU: %d %s %s %.*s\n",
170 	       task_thread_info(current)->cpu, print_tainted(),
171 	       init_utsname()->release,
172 	       (int)strcspn(init_utsname()->version, " "),
173 	       init_utsname()->version);
174 	printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
175 	       current->comm, current->pid, current,
176 	       (void *) current->thread.ksp);
177 	show_stack(NULL, NULL);
178 }
179 EXPORT_SYMBOL(dump_stack);
180 
181 static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
182 {
183 	return (regs->psw.mask & bits) / ((~bits + 1) & bits);
184 }
185 
186 void show_registers(struct pt_regs *regs)
187 {
188 	char *mode;
189 
190 	mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
191 	printk("%s PSW : %p %p",
192 	       mode, (void *) regs->psw.mask,
193 	       (void *) regs->psw.addr);
194 	print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
195 	printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
196 	       "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
197 	       mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
198 	       mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
199 	       mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
200 	       mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
201 	       mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
202 #ifdef CONFIG_64BIT
203 	printk(" EA:%x", mask_bits(regs, PSW_MASK_EA | PSW_MASK_BA));
204 #endif
205 	printk("\n%s GPRS: " FOURLONG, mode,
206 	       regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
207 	printk("           " FOURLONG,
208 	       regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
209 	printk("           " FOURLONG,
210 	       regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
211 	printk("           " FOURLONG,
212 	       regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
213 
214 	show_code(regs);
215 }
216 
217 void show_regs(struct pt_regs *regs)
218 {
219 	print_modules();
220 	printk("CPU: %d %s %s %.*s\n",
221 	       task_thread_info(current)->cpu, print_tainted(),
222 	       init_utsname()->release,
223 	       (int)strcspn(init_utsname()->version, " "),
224 	       init_utsname()->version);
225 	printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
226 	       current->comm, current->pid, current,
227 	       (void *) current->thread.ksp);
228 	show_registers(regs);
229 	/* Show stack backtrace if pt_regs is from kernel mode */
230 	if (!(regs->psw.mask & PSW_MASK_PSTATE))
231 		show_trace(NULL, (unsigned long *) regs->gprs[15]);
232 	show_last_breaking_event(regs);
233 }
234 
235 static DEFINE_SPINLOCK(die_lock);
236 
237 void die(const char * str, struct pt_regs * regs, long err)
238 {
239 	static int die_counter;
240 
241 	oops_enter();
242 	debug_stop_all();
243 	console_verbose();
244 	spin_lock_irq(&die_lock);
245 	bust_spinlocks(1);
246 	printk("%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
247 #ifdef CONFIG_PREEMPT
248 	printk("PREEMPT ");
249 #endif
250 #ifdef CONFIG_SMP
251 	printk("SMP ");
252 #endif
253 #ifdef CONFIG_DEBUG_PAGEALLOC
254 	printk("DEBUG_PAGEALLOC");
255 #endif
256 	printk("\n");
257 	notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
258 	show_regs(regs);
259 	bust_spinlocks(0);
260 	add_taint(TAINT_DIE);
261 	spin_unlock_irq(&die_lock);
262 	if (in_interrupt())
263 		panic("Fatal exception in interrupt");
264 	if (panic_on_oops)
265 		panic("Fatal exception: panic_on_oops");
266 	oops_exit();
267 	do_exit(SIGSEGV);
268 }
269 
270 static void inline report_user_fault(struct pt_regs *regs, long int_code,
271 				     int signr)
272 {
273 	if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
274 		return;
275 	if (!unhandled_signal(current, signr))
276 		return;
277 	if (!printk_ratelimit())
278 		return;
279 	printk("User process fault: interruption code 0x%lX ", int_code);
280 	print_vma_addr("in ", regs->psw.addr & PSW_ADDR_INSN);
281 	printk("\n");
282 	show_regs(regs);
283 }
284 
285 int is_valid_bugaddr(unsigned long addr)
286 {
287 	return 1;
288 }
289 
290 static inline void __kprobes do_trap(long pgm_int_code, int signr, char *str,
291 				     struct pt_regs *regs, siginfo_t *info)
292 {
293 	if (notify_die(DIE_TRAP, str, regs, pgm_int_code,
294 		       pgm_int_code, signr) == NOTIFY_STOP)
295 		return;
296 
297         if (regs->psw.mask & PSW_MASK_PSTATE) {
298                 struct task_struct *tsk = current;
299 
300 		tsk->thread.trap_no = pgm_int_code & 0xffff;
301 		force_sig_info(signr, info, tsk);
302 		report_user_fault(regs, pgm_int_code, signr);
303         } else {
304                 const struct exception_table_entry *fixup;
305                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
306                 if (fixup)
307                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
308 		else {
309 			enum bug_trap_type btt;
310 
311 			btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
312 			if (btt == BUG_TRAP_TYPE_WARN)
313 				return;
314 			die(str, regs, pgm_int_code);
315 		}
316         }
317 }
318 
319 static inline void __user *get_psw_address(struct pt_regs *regs,
320 					   long pgm_int_code)
321 {
322 	return (void __user *)
323 		((regs->psw.addr - (pgm_int_code >> 16)) & PSW_ADDR_INSN);
324 }
325 
326 void __kprobes do_per_trap(struct pt_regs *regs)
327 {
328 	siginfo_t info;
329 
330 	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
331 		return;
332 	if (!current->ptrace)
333 		return;
334 	info.si_signo = SIGTRAP;
335 	info.si_errno = 0;
336 	info.si_code = TRAP_HWBKPT;
337 	info.si_addr =
338 		(void __force __user *) current->thread.per_event.address;
339 	force_sig_info(SIGTRAP, &info, current);
340 }
341 
342 static void default_trap_handler(struct pt_regs *regs, long pgm_int_code,
343 				 unsigned long trans_exc_code)
344 {
345         if (regs->psw.mask & PSW_MASK_PSTATE) {
346 		report_user_fault(regs, pgm_int_code, SIGSEGV);
347 		do_exit(SIGSEGV);
348 	} else
349 		die("Unknown program exception", regs, pgm_int_code);
350 }
351 
352 #define DO_ERROR_INFO(name, signr, sicode, str) \
353 static void name(struct pt_regs *regs, long pgm_int_code, \
354 		 unsigned long trans_exc_code) \
355 { \
356         siginfo_t info; \
357         info.si_signo = signr; \
358         info.si_errno = 0; \
359         info.si_code = sicode; \
360 	info.si_addr = get_psw_address(regs, pgm_int_code); \
361 	do_trap(pgm_int_code, signr, str, regs, &info);	    \
362 }
363 
364 DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
365 	      "addressing exception")
366 DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
367 	      "execute exception")
368 DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
369 	      "fixpoint divide exception")
370 DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
371 	      "fixpoint overflow exception")
372 DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
373 	      "HFP overflow exception")
374 DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
375 	      "HFP underflow exception")
376 DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
377 	      "HFP significance exception")
378 DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
379 	      "HFP divide exception")
380 DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
381 	      "HFP square root exception")
382 DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
383 	      "operand exception")
384 DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
385 	      "privileged operation")
386 DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
387 	      "special operation exception")
388 DO_ERROR_INFO(translation_exception, SIGILL, ILL_ILLOPN,
389 	      "translation exception")
390 
391 static inline void do_fp_trap(struct pt_regs *regs, void __user *location,
392 			      int fpc, long pgm_int_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 	do_trap(pgm_int_code, SIGFPE,
415 		"floating point exception", regs, &si);
416 }
417 
418 static void __kprobes illegal_op(struct pt_regs *regs, long pgm_int_code,
419 				 unsigned long trans_exc_code)
420 {
421 	siginfo_t info;
422         __u8 opcode[6];
423 	__u16 __user *location;
424 	int signal = 0;
425 
426 	location = get_psw_address(regs, pgm_int_code);
427 
428 	if (regs->psw.mask & PSW_MASK_PSTATE) {
429 		if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
430 			return;
431 		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
432 			if (current->ptrace) {
433 				info.si_signo = SIGTRAP;
434 				info.si_errno = 0;
435 				info.si_code = TRAP_BRKPT;
436 				info.si_addr = location;
437 				force_sig_info(SIGTRAP, &info, current);
438 			} else
439 				signal = SIGILL;
440 #ifdef CONFIG_MATHEMU
441 		} else if (opcode[0] == 0xb3) {
442 			if (get_user(*((__u16 *) (opcode+2)), location+1))
443 				return;
444 			signal = math_emu_b3(opcode, regs);
445                 } else if (opcode[0] == 0xed) {
446 			if (get_user(*((__u32 *) (opcode+2)),
447 				     (__u32 __user *)(location+1)))
448 				return;
449 			signal = math_emu_ed(opcode, regs);
450 		} else if (*((__u16 *) opcode) == 0xb299) {
451 			if (get_user(*((__u16 *) (opcode+2)), location+1))
452 				return;
453 			signal = math_emu_srnm(opcode, regs);
454 		} else if (*((__u16 *) opcode) == 0xb29c) {
455 			if (get_user(*((__u16 *) (opcode+2)), location+1))
456 				return;
457 			signal = math_emu_stfpc(opcode, regs);
458 		} else if (*((__u16 *) opcode) == 0xb29d) {
459 			if (get_user(*((__u16 *) (opcode+2)), location+1))
460 				return;
461 			signal = math_emu_lfpc(opcode, regs);
462 #endif
463 		} else
464 			signal = SIGILL;
465 	} else {
466 		/*
467 		 * If we get an illegal op in kernel mode, send it through the
468 		 * kprobes notifier. If kprobes doesn't pick it up, SIGILL
469 		 */
470 		if (notify_die(DIE_BPT, "bpt", regs, pgm_int_code,
471 			       3, SIGTRAP) != NOTIFY_STOP)
472 			signal = SIGILL;
473 	}
474 
475 #ifdef CONFIG_MATHEMU
476         if (signal == SIGFPE)
477 		do_fp_trap(regs, location,
478 			   current->thread.fp_regs.fpc, pgm_int_code);
479         else if (signal == SIGSEGV) {
480 		info.si_signo = signal;
481 		info.si_errno = 0;
482 		info.si_code = SEGV_MAPERR;
483 		info.si_addr = (void __user *) location;
484 		do_trap(pgm_int_code, signal,
485 			"user address fault", regs, &info);
486 	} else
487 #endif
488         if (signal) {
489 		info.si_signo = signal;
490 		info.si_errno = 0;
491 		info.si_code = ILL_ILLOPC;
492 		info.si_addr = (void __user *) location;
493 		do_trap(pgm_int_code, signal,
494 			"illegal operation", regs, &info);
495 	}
496 }
497 
498 
499 #ifdef CONFIG_MATHEMU
500 void specification_exception(struct pt_regs *regs, long pgm_int_code,
501 			     unsigned long trans_exc_code)
502 {
503         __u8 opcode[6];
504 	__u16 __user *location = NULL;
505 	int signal = 0;
506 
507 	location = (__u16 __user *) get_psw_address(regs, pgm_int_code);
508 
509         if (regs->psw.mask & PSW_MASK_PSTATE) {
510 		get_user(*((__u16 *) opcode), location);
511 		switch (opcode[0]) {
512 		case 0x28: /* LDR Rx,Ry   */
513 			signal = math_emu_ldr(opcode);
514 			break;
515 		case 0x38: /* LER Rx,Ry   */
516 			signal = math_emu_ler(opcode);
517 			break;
518 		case 0x60: /* STD R,D(X,B) */
519 			get_user(*((__u16 *) (opcode+2)), location+1);
520 			signal = math_emu_std(opcode, regs);
521 			break;
522 		case 0x68: /* LD R,D(X,B) */
523 			get_user(*((__u16 *) (opcode+2)), location+1);
524 			signal = math_emu_ld(opcode, regs);
525 			break;
526 		case 0x70: /* STE R,D(X,B) */
527 			get_user(*((__u16 *) (opcode+2)), location+1);
528 			signal = math_emu_ste(opcode, regs);
529 			break;
530 		case 0x78: /* LE R,D(X,B) */
531 			get_user(*((__u16 *) (opcode+2)), location+1);
532 			signal = math_emu_le(opcode, regs);
533 			break;
534 		default:
535 			signal = SIGILL;
536 			break;
537                 }
538         } else
539 		signal = SIGILL;
540 
541         if (signal == SIGFPE)
542 		do_fp_trap(regs, location,
543 			   current->thread.fp_regs.fpc, pgm_int_code);
544         else if (signal) {
545 		siginfo_t info;
546 		info.si_signo = signal;
547 		info.si_errno = 0;
548 		info.si_code = ILL_ILLOPN;
549 		info.si_addr = location;
550 		do_trap(pgm_int_code, signal,
551 			"specification exception", regs, &info);
552 	}
553 }
554 #else
555 DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
556 	      "specification exception");
557 #endif
558 
559 static void data_exception(struct pt_regs *regs, long pgm_int_code,
560 			   unsigned long trans_exc_code)
561 {
562 	__u16 __user *location;
563 	int signal = 0;
564 
565 	location = get_psw_address(regs, pgm_int_code);
566 
567 	if (MACHINE_HAS_IEEE)
568 		asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
569 
570 #ifdef CONFIG_MATHEMU
571         else if (regs->psw.mask & PSW_MASK_PSTATE) {
572         	__u8 opcode[6];
573 		get_user(*((__u16 *) opcode), location);
574 		switch (opcode[0]) {
575 		case 0x28: /* LDR Rx,Ry   */
576 			signal = math_emu_ldr(opcode);
577 			break;
578 		case 0x38: /* LER Rx,Ry   */
579 			signal = math_emu_ler(opcode);
580 			break;
581 		case 0x60: /* STD R,D(X,B) */
582 			get_user(*((__u16 *) (opcode+2)), location+1);
583 			signal = math_emu_std(opcode, regs);
584 			break;
585 		case 0x68: /* LD R,D(X,B) */
586 			get_user(*((__u16 *) (opcode+2)), location+1);
587 			signal = math_emu_ld(opcode, regs);
588 			break;
589 		case 0x70: /* STE R,D(X,B) */
590 			get_user(*((__u16 *) (opcode+2)), location+1);
591 			signal = math_emu_ste(opcode, regs);
592 			break;
593 		case 0x78: /* LE R,D(X,B) */
594 			get_user(*((__u16 *) (opcode+2)), location+1);
595 			signal = math_emu_le(opcode, regs);
596 			break;
597 		case 0xb3:
598 			get_user(*((__u16 *) (opcode+2)), location+1);
599 			signal = math_emu_b3(opcode, regs);
600 			break;
601                 case 0xed:
602 			get_user(*((__u32 *) (opcode+2)),
603 				 (__u32 __user *)(location+1));
604 			signal = math_emu_ed(opcode, regs);
605 			break;
606 	        case 0xb2:
607 			if (opcode[1] == 0x99) {
608 				get_user(*((__u16 *) (opcode+2)), location+1);
609 				signal = math_emu_srnm(opcode, regs);
610 			} else if (opcode[1] == 0x9c) {
611 				get_user(*((__u16 *) (opcode+2)), location+1);
612 				signal = math_emu_stfpc(opcode, regs);
613 			} else if (opcode[1] == 0x9d) {
614 				get_user(*((__u16 *) (opcode+2)), location+1);
615 				signal = math_emu_lfpc(opcode, regs);
616 			} else
617 				signal = SIGILL;
618 			break;
619 		default:
620 			signal = SIGILL;
621 			break;
622                 }
623         }
624 #endif
625 	if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
626 		signal = SIGFPE;
627 	else
628 		signal = SIGILL;
629         if (signal == SIGFPE)
630 		do_fp_trap(regs, location,
631 			   current->thread.fp_regs.fpc, pgm_int_code);
632         else if (signal) {
633 		siginfo_t info;
634 		info.si_signo = signal;
635 		info.si_errno = 0;
636 		info.si_code = ILL_ILLOPN;
637 		info.si_addr = location;
638 		do_trap(pgm_int_code, signal, "data exception", regs, &info);
639 	}
640 }
641 
642 static void space_switch_exception(struct pt_regs *regs, long pgm_int_code,
643 				   unsigned long trans_exc_code)
644 {
645         siginfo_t info;
646 
647 	/* Set user psw back to home space mode. */
648 	if (regs->psw.mask & PSW_MASK_PSTATE)
649 		regs->psw.mask |= PSW_ASC_HOME;
650 	/* Send SIGILL. */
651         info.si_signo = SIGILL;
652         info.si_errno = 0;
653         info.si_code = ILL_PRVOPC;
654 	info.si_addr = get_psw_address(regs, pgm_int_code);
655 	do_trap(pgm_int_code, SIGILL, "space switch event", regs, &info);
656 }
657 
658 void __kprobes kernel_stack_overflow(struct pt_regs * regs)
659 {
660 	bust_spinlocks(1);
661 	printk("Kernel stack overflow.\n");
662 	show_regs(regs);
663 	bust_spinlocks(0);
664 	panic("Corrupt kernel stack, can't continue.");
665 }
666 
667 /* init is done in lowcore.S and head.S */
668 
669 void __init trap_init(void)
670 {
671         int i;
672 
673         for (i = 0; i < 128; i++)
674           pgm_check_table[i] = &default_trap_handler;
675         pgm_check_table[1] = &illegal_op;
676         pgm_check_table[2] = &privileged_op;
677         pgm_check_table[3] = &execute_exception;
678         pgm_check_table[4] = &do_protection_exception;
679         pgm_check_table[5] = &addressing_exception;
680         pgm_check_table[6] = &specification_exception;
681         pgm_check_table[7] = &data_exception;
682         pgm_check_table[8] = &overflow_exception;
683         pgm_check_table[9] = &divide_exception;
684         pgm_check_table[0x0A] = &overflow_exception;
685         pgm_check_table[0x0B] = &divide_exception;
686         pgm_check_table[0x0C] = &hfp_overflow_exception;
687         pgm_check_table[0x0D] = &hfp_underflow_exception;
688         pgm_check_table[0x0E] = &hfp_significance_exception;
689         pgm_check_table[0x0F] = &hfp_divide_exception;
690         pgm_check_table[0x10] = &do_dat_exception;
691         pgm_check_table[0x11] = &do_dat_exception;
692         pgm_check_table[0x12] = &translation_exception;
693         pgm_check_table[0x13] = &special_op_exception;
694 #ifdef CONFIG_64BIT
695 	pgm_check_table[0x38] = &do_asce_exception;
696 	pgm_check_table[0x39] = &do_dat_exception;
697 	pgm_check_table[0x3A] = &do_dat_exception;
698         pgm_check_table[0x3B] = &do_dat_exception;
699 #endif /* CONFIG_64BIT */
700         pgm_check_table[0x15] = &operand_exception;
701         pgm_check_table[0x1C] = &space_switch_exception;
702         pgm_check_table[0x1D] = &hfp_sqrt_exception;
703 	/* Enable machine checks early. */
704 	local_mcck_enable();
705 }
706