xref: /openbmc/linux/arch/s390/kernel/traps.c (revision 05bcf503)
1 /*
2  *  S390 version
3  *    Copyright IBM Corp. 1999, 2000
4  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
5  *               Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
6  *
7  *  Derived from "arch/i386/kernel/traps.c"
8  *    Copyright (C) 1991, 1992 Linus Torvalds
9  */
10 
11 /*
12  * 'Traps.c' handles hardware traps and faults after we have saved some
13  * state in 'asm.s'.
14  */
15 #include <linux/sched.h>
16 #include <linux/kernel.h>
17 #include <linux/string.h>
18 #include <linux/errno.h>
19 #include <linux/ptrace.h>
20 #include <linux/timer.h>
21 #include <linux/mm.h>
22 #include <linux/smp.h>
23 #include <linux/init.h>
24 #include <linux/interrupt.h>
25 #include <linux/seq_file.h>
26 #include <linux/delay.h>
27 #include <linux/module.h>
28 #include <linux/kdebug.h>
29 #include <linux/kallsyms.h>
30 #include <linux/reboot.h>
31 #include <linux/kprobes.h>
32 #include <linux/bug.h>
33 #include <linux/utsname.h>
34 #include <asm/uaccess.h>
35 #include <asm/io.h>
36 #include <linux/atomic.h>
37 #include <asm/mathemu.h>
38 #include <asm/cpcmd.h>
39 #include <asm/lowcore.h>
40 #include <asm/debug.h>
41 #include <asm/ipl.h>
42 #include "entry.h"
43 
44 void (*pgm_check_table[128])(struct pt_regs *regs);
45 
46 int show_unhandled_signals = 1;
47 
48 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
49 
50 #ifndef CONFIG_64BIT
51 #define LONG "%08lx "
52 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
53 static int kstack_depth_to_print = 12;
54 #else /* CONFIG_64BIT */
55 #define LONG "%016lx "
56 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
57 static int kstack_depth_to_print = 20;
58 #endif /* CONFIG_64BIT */
59 
60 static inline void __user *get_trap_ip(struct pt_regs *regs)
61 {
62 #ifdef CONFIG_64BIT
63 	unsigned long address;
64 
65 	if (regs->int_code & 0x200)
66 		address = *(unsigned long *)(current->thread.trap_tdb + 24);
67 	else
68 		address = regs->psw.addr;
69 	return (void __user *)
70 		((address - (regs->int_code >> 16)) & PSW_ADDR_INSN);
71 #else
72 	return (void __user *)
73 		((regs->psw.addr - (regs->int_code >> 16)) & PSW_ADDR_INSN);
74 #endif
75 }
76 
77 /*
78  * For show_trace we have tree different stack to consider:
79  *   - the panic stack which is used if the kernel stack has overflown
80  *   - the asynchronous interrupt stack (cpu related)
81  *   - the synchronous kernel stack (process related)
82  * The stack trace can start at any of the three stack and can potentially
83  * touch all of them. The order is: panic stack, async stack, sync stack.
84  */
85 static unsigned long
86 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
87 {
88 	struct stack_frame *sf;
89 	struct pt_regs *regs;
90 
91 	while (1) {
92 		sp = sp & PSW_ADDR_INSN;
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 		/* Follow the backchain. */
99 		while (1) {
100 			low = sp;
101 			sp = sf->back_chain & PSW_ADDR_INSN;
102 			if (!sp)
103 				break;
104 			if (sp <= low || sp > high - sizeof(*sf))
105 				return sp;
106 			sf = (struct stack_frame *) sp;
107 			printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
108 			print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
109 		}
110 		/* Zero backchain detected, check for interrupt frame. */
111 		sp = (unsigned long) (sf + 1);
112 		if (sp <= low || sp > high - sizeof(*regs))
113 			return sp;
114 		regs = (struct pt_regs *) sp;
115 		printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
116 		print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
117 		low = sp;
118 		sp = regs->gprs[15];
119 	}
120 }
121 
122 static void show_trace(struct task_struct *task, unsigned long *stack)
123 {
124 	register unsigned long __r15 asm ("15");
125 	unsigned long sp;
126 
127 	sp = (unsigned long) stack;
128 	if (!sp)
129 		sp = task ? task->thread.ksp : __r15;
130 	printk("Call Trace:\n");
131 #ifdef CONFIG_CHECK_STACK
132 	sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
133 			  S390_lowcore.panic_stack);
134 #endif
135 	sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
136 			  S390_lowcore.async_stack);
137 	if (task)
138 		__show_trace(sp, (unsigned long) task_stack_page(task),
139 			     (unsigned long) task_stack_page(task) + THREAD_SIZE);
140 	else
141 		__show_trace(sp, S390_lowcore.thread_info,
142 			     S390_lowcore.thread_info + THREAD_SIZE);
143 	if (!task)
144 		task = current;
145 	debug_show_held_locks(task);
146 }
147 
148 void show_stack(struct task_struct *task, unsigned long *sp)
149 {
150 	register unsigned long * __r15 asm ("15");
151 	unsigned long *stack;
152 	int i;
153 
154 	if (!sp)
155 		stack = task ? (unsigned long *) task->thread.ksp : __r15;
156 	else
157 		stack = sp;
158 
159 	for (i = 0; i < kstack_depth_to_print; i++) {
160 		if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
161 			break;
162 		if ((i * sizeof(long) % 32) == 0)
163 			printk("%s       ", i == 0 ? "" : "\n");
164 		printk(LONG, *stack++);
165 	}
166 	printk("\n");
167 	show_trace(task, sp);
168 }
169 
170 static void show_last_breaking_event(struct pt_regs *regs)
171 {
172 #ifdef CONFIG_64BIT
173 	printk("Last Breaking-Event-Address:\n");
174 	printk(" [<%016lx>] ", regs->args[0] & PSW_ADDR_INSN);
175 	print_symbol("%s\n", regs->args[0] & PSW_ADDR_INSN);
176 #endif
177 }
178 
179 /*
180  * The architecture-independent dump_stack generator
181  */
182 void dump_stack(void)
183 {
184 	printk("CPU: %d %s %s %.*s\n",
185 	       task_thread_info(current)->cpu, print_tainted(),
186 	       init_utsname()->release,
187 	       (int)strcspn(init_utsname()->version, " "),
188 	       init_utsname()->version);
189 	printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
190 	       current->comm, current->pid, current,
191 	       (void *) current->thread.ksp);
192 	show_stack(NULL, NULL);
193 }
194 EXPORT_SYMBOL(dump_stack);
195 
196 static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
197 {
198 	return (regs->psw.mask & bits) / ((~bits + 1) & bits);
199 }
200 
201 void show_registers(struct pt_regs *regs)
202 {
203 	char *mode;
204 
205 	mode = user_mode(regs) ? "User" : "Krnl";
206 	printk("%s PSW : %p %p",
207 	       mode, (void *) regs->psw.mask,
208 	       (void *) regs->psw.addr);
209 	print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
210 	printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
211 	       "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
212 	       mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
213 	       mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
214 	       mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
215 	       mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
216 	       mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
217 #ifdef CONFIG_64BIT
218 	printk(" EA:%x", mask_bits(regs, PSW_MASK_EA | PSW_MASK_BA));
219 #endif
220 	printk("\n%s GPRS: " FOURLONG, mode,
221 	       regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
222 	printk("           " FOURLONG,
223 	       regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
224 	printk("           " FOURLONG,
225 	       regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
226 	printk("           " FOURLONG,
227 	       regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
228 
229 	show_code(regs);
230 }
231 
232 void show_regs(struct pt_regs *regs)
233 {
234 	printk("CPU: %d %s %s %.*s\n",
235 	       task_thread_info(current)->cpu, print_tainted(),
236 	       init_utsname()->release,
237 	       (int)strcspn(init_utsname()->version, " "),
238 	       init_utsname()->version);
239 	printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
240 	       current->comm, current->pid, current,
241 	       (void *) current->thread.ksp);
242 	show_registers(regs);
243 	/* Show stack backtrace if pt_regs is from kernel mode */
244 	if (!user_mode(regs))
245 		show_trace(NULL, (unsigned long *) regs->gprs[15]);
246 	show_last_breaking_event(regs);
247 }
248 
249 static DEFINE_SPINLOCK(die_lock);
250 
251 void die(struct pt_regs *regs, const char *str)
252 {
253 	static int die_counter;
254 
255 	oops_enter();
256 	lgr_info_log();
257 	debug_stop_all();
258 	console_verbose();
259 	spin_lock_irq(&die_lock);
260 	bust_spinlocks(1);
261 	printk("%s: %04x [#%d] ", str, regs->int_code & 0xffff, ++die_counter);
262 #ifdef CONFIG_PREEMPT
263 	printk("PREEMPT ");
264 #endif
265 #ifdef CONFIG_SMP
266 	printk("SMP ");
267 #endif
268 #ifdef CONFIG_DEBUG_PAGEALLOC
269 	printk("DEBUG_PAGEALLOC");
270 #endif
271 	printk("\n");
272 	notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
273 	print_modules();
274 	show_regs(regs);
275 	bust_spinlocks(0);
276 	add_taint(TAINT_DIE);
277 	spin_unlock_irq(&die_lock);
278 	if (in_interrupt())
279 		panic("Fatal exception in interrupt");
280 	if (panic_on_oops)
281 		panic("Fatal exception: panic_on_oops");
282 	oops_exit();
283 	do_exit(SIGSEGV);
284 }
285 
286 static inline void report_user_fault(struct pt_regs *regs, int signr)
287 {
288 	if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
289 		return;
290 	if (!unhandled_signal(current, signr))
291 		return;
292 	if (!printk_ratelimit())
293 		return;
294 	printk("User process fault: interruption code 0x%X ", regs->int_code);
295 	print_vma_addr("in ", regs->psw.addr & PSW_ADDR_INSN);
296 	printk("\n");
297 	show_regs(regs);
298 }
299 
300 int is_valid_bugaddr(unsigned long addr)
301 {
302 	return 1;
303 }
304 
305 static void __kprobes do_trap(struct pt_regs *regs,
306 			      int si_signo, int si_code, char *str)
307 {
308 	siginfo_t info;
309 
310 	if (notify_die(DIE_TRAP, str, regs, 0,
311 		       regs->int_code, si_signo) == NOTIFY_STOP)
312 		return;
313 
314 	if (user_mode(regs)) {
315 		info.si_signo = si_signo;
316 		info.si_errno = 0;
317 		info.si_code = si_code;
318 		info.si_addr = get_trap_ip(regs);
319 		force_sig_info(si_signo, &info, current);
320 		report_user_fault(regs, si_signo);
321         } else {
322                 const struct exception_table_entry *fixup;
323                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
324                 if (fixup)
325 			regs->psw.addr = extable_fixup(fixup) | PSW_ADDR_AMODE;
326 		else {
327 			enum bug_trap_type btt;
328 
329 			btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
330 			if (btt == BUG_TRAP_TYPE_WARN)
331 				return;
332 			die(regs, str);
333 		}
334         }
335 }
336 
337 void __kprobes do_per_trap(struct pt_regs *regs)
338 {
339 	siginfo_t info;
340 
341 	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
342 		return;
343 	if (!current->ptrace)
344 		return;
345 	info.si_signo = SIGTRAP;
346 	info.si_errno = 0;
347 	info.si_code = TRAP_HWBKPT;
348 	info.si_addr =
349 		(void __force __user *) current->thread.per_event.address;
350 	force_sig_info(SIGTRAP, &info, current);
351 }
352 
353 static void default_trap_handler(struct pt_regs *regs)
354 {
355 	if (user_mode(regs)) {
356 		report_user_fault(regs, SIGSEGV);
357 		do_exit(SIGSEGV);
358 	} else
359 		die(regs, "Unknown program exception");
360 }
361 
362 #define DO_ERROR_INFO(name, signr, sicode, str) \
363 static void name(struct pt_regs *regs) \
364 { \
365 	do_trap(regs, signr, sicode, str); \
366 }
367 
368 DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
369 	      "addressing exception")
370 DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
371 	      "execute exception")
372 DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
373 	      "fixpoint divide exception")
374 DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
375 	      "fixpoint overflow exception")
376 DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
377 	      "HFP overflow exception")
378 DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
379 	      "HFP underflow exception")
380 DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
381 	      "HFP significance exception")
382 DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
383 	      "HFP divide exception")
384 DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
385 	      "HFP square root exception")
386 DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
387 	      "operand exception")
388 DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
389 	      "privileged operation")
390 DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
391 	      "special operation exception")
392 DO_ERROR_INFO(translation_exception, SIGILL, ILL_ILLOPN,
393 	      "translation exception")
394 
395 #ifdef CONFIG_64BIT
396 DO_ERROR_INFO(transaction_exception, SIGILL, ILL_ILLOPN,
397 	      "transaction constraint exception")
398 #endif
399 
400 static inline void do_fp_trap(struct pt_regs *regs, int fpc)
401 {
402 	int si_code = 0;
403 	/* FPC[2] is Data Exception Code */
404 	if ((fpc & 0x00000300) == 0) {
405 		/* bits 6 and 7 of DXC are 0 iff IEEE exception */
406 		if (fpc & 0x8000) /* invalid fp operation */
407 			si_code = FPE_FLTINV;
408 		else if (fpc & 0x4000) /* div by 0 */
409 			si_code = FPE_FLTDIV;
410 		else if (fpc & 0x2000) /* overflow */
411 			si_code = FPE_FLTOVF;
412 		else if (fpc & 0x1000) /* underflow */
413 			si_code = FPE_FLTUND;
414 		else if (fpc & 0x0800) /* inexact */
415 			si_code = FPE_FLTRES;
416 	}
417 	do_trap(regs, SIGFPE, si_code, "floating point exception");
418 }
419 
420 static void __kprobes illegal_op(struct pt_regs *regs)
421 {
422 	siginfo_t info;
423         __u8 opcode[6];
424 	__u16 __user *location;
425 	int signal = 0;
426 
427 	location = get_trap_ip(regs);
428 
429 	if (user_mode(regs)) {
430 		if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
431 			return;
432 		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
433 			if (current->ptrace) {
434 				info.si_signo = SIGTRAP;
435 				info.si_errno = 0;
436 				info.si_code = TRAP_BRKPT;
437 				info.si_addr = location;
438 				force_sig_info(SIGTRAP, &info, current);
439 			} else
440 				signal = SIGILL;
441 #ifdef CONFIG_MATHEMU
442 		} else if (opcode[0] == 0xb3) {
443 			if (get_user(*((__u16 *) (opcode+2)), location+1))
444 				return;
445 			signal = math_emu_b3(opcode, regs);
446                 } else if (opcode[0] == 0xed) {
447 			if (get_user(*((__u32 *) (opcode+2)),
448 				     (__u32 __user *)(location+1)))
449 				return;
450 			signal = math_emu_ed(opcode, regs);
451 		} else if (*((__u16 *) opcode) == 0xb299) {
452 			if (get_user(*((__u16 *) (opcode+2)), location+1))
453 				return;
454 			signal = math_emu_srnm(opcode, regs);
455 		} else if (*((__u16 *) opcode) == 0xb29c) {
456 			if (get_user(*((__u16 *) (opcode+2)), location+1))
457 				return;
458 			signal = math_emu_stfpc(opcode, regs);
459 		} else if (*((__u16 *) opcode) == 0xb29d) {
460 			if (get_user(*((__u16 *) (opcode+2)), location+1))
461 				return;
462 			signal = math_emu_lfpc(opcode, regs);
463 #endif
464 		} else
465 			signal = SIGILL;
466 	} else {
467 		/*
468 		 * If we get an illegal op in kernel mode, send it through the
469 		 * kprobes notifier. If kprobes doesn't pick it up, SIGILL
470 		 */
471 		if (notify_die(DIE_BPT, "bpt", regs, 0,
472 			       3, SIGTRAP) != NOTIFY_STOP)
473 			signal = SIGILL;
474 	}
475 
476 #ifdef CONFIG_MATHEMU
477         if (signal == SIGFPE)
478 		do_fp_trap(regs, current->thread.fp_regs.fpc);
479 	else if (signal == SIGSEGV)
480 		do_trap(regs, signal, SEGV_MAPERR, "user address fault");
481 	else
482 #endif
483 	if (signal)
484 		do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
485 }
486 
487 
488 #ifdef CONFIG_MATHEMU
489 void specification_exception(struct pt_regs *regs)
490 {
491         __u8 opcode[6];
492 	__u16 __user *location = NULL;
493 	int signal = 0;
494 
495 	location = (__u16 __user *) get_trap_ip(regs);
496 
497 	if (user_mode(regs)) {
498 		get_user(*((__u16 *) opcode), location);
499 		switch (opcode[0]) {
500 		case 0x28: /* LDR Rx,Ry   */
501 			signal = math_emu_ldr(opcode);
502 			break;
503 		case 0x38: /* LER Rx,Ry   */
504 			signal = math_emu_ler(opcode);
505 			break;
506 		case 0x60: /* STD R,D(X,B) */
507 			get_user(*((__u16 *) (opcode+2)), location+1);
508 			signal = math_emu_std(opcode, regs);
509 			break;
510 		case 0x68: /* LD R,D(X,B) */
511 			get_user(*((__u16 *) (opcode+2)), location+1);
512 			signal = math_emu_ld(opcode, regs);
513 			break;
514 		case 0x70: /* STE R,D(X,B) */
515 			get_user(*((__u16 *) (opcode+2)), location+1);
516 			signal = math_emu_ste(opcode, regs);
517 			break;
518 		case 0x78: /* LE R,D(X,B) */
519 			get_user(*((__u16 *) (opcode+2)), location+1);
520 			signal = math_emu_le(opcode, regs);
521 			break;
522 		default:
523 			signal = SIGILL;
524 			break;
525                 }
526         } else
527 		signal = SIGILL;
528 
529         if (signal == SIGFPE)
530 		do_fp_trap(regs, current->thread.fp_regs.fpc);
531 	else if (signal)
532 		do_trap(regs, signal, ILL_ILLOPN, "specification exception");
533 }
534 #else
535 DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
536 	      "specification exception");
537 #endif
538 
539 static void data_exception(struct pt_regs *regs)
540 {
541 	__u16 __user *location;
542 	int signal = 0;
543 
544 	location = get_trap_ip(regs);
545 
546 	if (MACHINE_HAS_IEEE)
547 		asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
548 
549 #ifdef CONFIG_MATHEMU
550 	else if (user_mode(regs)) {
551         	__u8 opcode[6];
552 		get_user(*((__u16 *) opcode), location);
553 		switch (opcode[0]) {
554 		case 0x28: /* LDR Rx,Ry   */
555 			signal = math_emu_ldr(opcode);
556 			break;
557 		case 0x38: /* LER Rx,Ry   */
558 			signal = math_emu_ler(opcode);
559 			break;
560 		case 0x60: /* STD R,D(X,B) */
561 			get_user(*((__u16 *) (opcode+2)), location+1);
562 			signal = math_emu_std(opcode, regs);
563 			break;
564 		case 0x68: /* LD R,D(X,B) */
565 			get_user(*((__u16 *) (opcode+2)), location+1);
566 			signal = math_emu_ld(opcode, regs);
567 			break;
568 		case 0x70: /* STE R,D(X,B) */
569 			get_user(*((__u16 *) (opcode+2)), location+1);
570 			signal = math_emu_ste(opcode, regs);
571 			break;
572 		case 0x78: /* LE R,D(X,B) */
573 			get_user(*((__u16 *) (opcode+2)), location+1);
574 			signal = math_emu_le(opcode, regs);
575 			break;
576 		case 0xb3:
577 			get_user(*((__u16 *) (opcode+2)), location+1);
578 			signal = math_emu_b3(opcode, regs);
579 			break;
580                 case 0xed:
581 			get_user(*((__u32 *) (opcode+2)),
582 				 (__u32 __user *)(location+1));
583 			signal = math_emu_ed(opcode, regs);
584 			break;
585 	        case 0xb2:
586 			if (opcode[1] == 0x99) {
587 				get_user(*((__u16 *) (opcode+2)), location+1);
588 				signal = math_emu_srnm(opcode, regs);
589 			} else if (opcode[1] == 0x9c) {
590 				get_user(*((__u16 *) (opcode+2)), location+1);
591 				signal = math_emu_stfpc(opcode, regs);
592 			} else if (opcode[1] == 0x9d) {
593 				get_user(*((__u16 *) (opcode+2)), location+1);
594 				signal = math_emu_lfpc(opcode, regs);
595 			} else
596 				signal = SIGILL;
597 			break;
598 		default:
599 			signal = SIGILL;
600 			break;
601                 }
602         }
603 #endif
604 	if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
605 		signal = SIGFPE;
606 	else
607 		signal = SIGILL;
608         if (signal == SIGFPE)
609 		do_fp_trap(regs, current->thread.fp_regs.fpc);
610 	else if (signal)
611 		do_trap(regs, signal, ILL_ILLOPN, "data exception");
612 }
613 
614 static void space_switch_exception(struct pt_regs *regs)
615 {
616 	/* Set user psw back to home space mode. */
617 	if (user_mode(regs))
618 		regs->psw.mask |= PSW_ASC_HOME;
619 	/* Send SIGILL. */
620 	do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event");
621 }
622 
623 void __kprobes kernel_stack_overflow(struct pt_regs * regs)
624 {
625 	bust_spinlocks(1);
626 	printk("Kernel stack overflow.\n");
627 	show_regs(regs);
628 	bust_spinlocks(0);
629 	panic("Corrupt kernel stack, can't continue.");
630 }
631 
632 /* init is done in lowcore.S and head.S */
633 
634 void __init trap_init(void)
635 {
636         int i;
637 
638         for (i = 0; i < 128; i++)
639           pgm_check_table[i] = &default_trap_handler;
640         pgm_check_table[1] = &illegal_op;
641         pgm_check_table[2] = &privileged_op;
642         pgm_check_table[3] = &execute_exception;
643         pgm_check_table[4] = &do_protection_exception;
644         pgm_check_table[5] = &addressing_exception;
645         pgm_check_table[6] = &specification_exception;
646         pgm_check_table[7] = &data_exception;
647         pgm_check_table[8] = &overflow_exception;
648         pgm_check_table[9] = &divide_exception;
649         pgm_check_table[0x0A] = &overflow_exception;
650         pgm_check_table[0x0B] = &divide_exception;
651         pgm_check_table[0x0C] = &hfp_overflow_exception;
652         pgm_check_table[0x0D] = &hfp_underflow_exception;
653         pgm_check_table[0x0E] = &hfp_significance_exception;
654         pgm_check_table[0x0F] = &hfp_divide_exception;
655         pgm_check_table[0x10] = &do_dat_exception;
656         pgm_check_table[0x11] = &do_dat_exception;
657         pgm_check_table[0x12] = &translation_exception;
658         pgm_check_table[0x13] = &special_op_exception;
659 #ifdef CONFIG_64BIT
660 	pgm_check_table[0x18] = &transaction_exception;
661 	pgm_check_table[0x38] = &do_asce_exception;
662 	pgm_check_table[0x39] = &do_dat_exception;
663 	pgm_check_table[0x3A] = &do_dat_exception;
664         pgm_check_table[0x3B] = &do_dat_exception;
665 #endif /* CONFIG_64BIT */
666         pgm_check_table[0x15] = &operand_exception;
667         pgm_check_table[0x1C] = &space_switch_exception;
668         pgm_check_table[0x1D] = &hfp_sqrt_exception;
669 	/* Enable machine checks early. */
670 	local_mcck_enable();
671 }
672