xref: /linux/arch/s390/kernel/traps.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
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/smp_lock.h>
26 #include <linux/init.h>
27 #include <linux/interrupt.h>
28 #include <linux/delay.h>
29 #include <linux/module.h>
30 #include <linux/kallsyms.h>
31 #include <linux/reboot.h>
32 
33 #include <asm/system.h>
34 #include <asm/uaccess.h>
35 #include <asm/io.h>
36 #include <asm/atomic.h>
37 #include <asm/mathemu.h>
38 #include <asm/cpcmd.h>
39 #include <asm/s390_ext.h>
40 #include <asm/lowcore.h>
41 #include <asm/debug.h>
42 
43 /* Called from entry.S only */
44 extern void handle_per_exception(struct pt_regs *regs);
45 
46 typedef void pgm_check_handler_t(struct pt_regs *, long);
47 pgm_check_handler_t *pgm_check_table[128];
48 
49 #ifdef CONFIG_SYSCTL
50 #ifdef CONFIG_PROCESS_DEBUG
51 int sysctl_userprocess_debug = 1;
52 #else
53 int sysctl_userprocess_debug = 0;
54 #endif
55 #endif
56 
57 extern pgm_check_handler_t do_protection_exception;
58 extern pgm_check_handler_t do_dat_exception;
59 #ifdef CONFIG_PFAULT
60 extern int pfault_init(void);
61 extern void pfault_fini(void);
62 extern void pfault_interrupt(struct pt_regs *regs, __u16 error_code);
63 static ext_int_info_t ext_int_pfault;
64 #endif
65 extern pgm_check_handler_t do_monitor_call;
66 
67 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
68 
69 #ifndef CONFIG_64BIT
70 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
71 static int kstack_depth_to_print = 12;
72 #else /* CONFIG_64BIT */
73 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
74 static int kstack_depth_to_print = 20;
75 #endif /* CONFIG_64BIT */
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 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 	printk("\n");
144 }
145 
146 void show_stack(struct task_struct *task, unsigned long *sp)
147 {
148 	register unsigned long * __r15 asm ("15");
149 	unsigned long *stack;
150 	int i;
151 
152 	if (!sp)
153 		stack = task ? (unsigned long *) task->thread.ksp : __r15;
154 	else
155 		stack = sp;
156 
157 	for (i = 0; i < kstack_depth_to_print; i++) {
158 		if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
159 			break;
160 		if (i && ((i * sizeof (long) % 32) == 0))
161 			printk("\n       ");
162 		printk("%p ", (void *)*stack++);
163 	}
164 	printk("\n");
165 	show_trace(task, sp);
166 }
167 
168 /*
169  * The architecture-independent dump_stack generator
170  */
171 void dump_stack(void)
172 {
173 	show_stack(0, 0);
174 }
175 
176 EXPORT_SYMBOL(dump_stack);
177 
178 void show_registers(struct pt_regs *regs)
179 {
180 	mm_segment_t old_fs;
181 	char *mode;
182 	int i;
183 
184 	mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
185 	printk("%s PSW : %p %p",
186 	       mode, (void *) regs->psw.mask,
187 	       (void *) regs->psw.addr);
188 	print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
189 	printk("%s GPRS: " FOURLONG, mode,
190 	       regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
191 	printk("           " FOURLONG,
192 	       regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
193 	printk("           " FOURLONG,
194 	       regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
195 	printk("           " FOURLONG,
196 	       regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
197 
198 #if 0
199 	/* FIXME: this isn't needed any more but it changes the ksymoops
200 	 * input. To remove or not to remove ... */
201 	save_access_regs(regs->acrs);
202 	printk("%s ACRS: %08x %08x %08x %08x\n", mode,
203 	       regs->acrs[0], regs->acrs[1], regs->acrs[2], regs->acrs[3]);
204 	printk("           %08x %08x %08x %08x\n",
205 	       regs->acrs[4], regs->acrs[5], regs->acrs[6], regs->acrs[7]);
206 	printk("           %08x %08x %08x %08x\n",
207 	       regs->acrs[8], regs->acrs[9], regs->acrs[10], regs->acrs[11]);
208 	printk("           %08x %08x %08x %08x\n",
209 	       regs->acrs[12], regs->acrs[13], regs->acrs[14], regs->acrs[15]);
210 #endif
211 
212 	/*
213 	 * Print the first 20 byte of the instruction stream at the
214 	 * time of the fault.
215 	 */
216 	old_fs = get_fs();
217 	if (regs->psw.mask & PSW_MASK_PSTATE)
218 		set_fs(USER_DS);
219 	else
220 		set_fs(KERNEL_DS);
221 	printk("%s Code: ", mode);
222 	for (i = 0; i < 20; i++) {
223 		unsigned char c;
224 		if (__get_user(c, (char __user *)(regs->psw.addr + i))) {
225 			printk(" Bad PSW.");
226 			break;
227 		}
228 		printk("%02x ", c);
229 	}
230 	set_fs(old_fs);
231 
232 	printk("\n");
233 }
234 
235 /* This is called from fs/proc/array.c */
236 char *task_show_regs(struct task_struct *task, char *buffer)
237 {
238 	struct pt_regs *regs;
239 
240 	regs = task_pt_regs(task);
241 	buffer += sprintf(buffer, "task: %p, ksp: %p\n",
242 		       task, (void *)task->thread.ksp);
243 	buffer += sprintf(buffer, "User PSW : %p %p\n",
244 		       (void *) regs->psw.mask, (void *)regs->psw.addr);
245 
246 	buffer += sprintf(buffer, "User GPRS: " FOURLONG,
247 			  regs->gprs[0], regs->gprs[1],
248 			  regs->gprs[2], regs->gprs[3]);
249 	buffer += sprintf(buffer, "           " FOURLONG,
250 			  regs->gprs[4], regs->gprs[5],
251 			  regs->gprs[6], regs->gprs[7]);
252 	buffer += sprintf(buffer, "           " FOURLONG,
253 			  regs->gprs[8], regs->gprs[9],
254 			  regs->gprs[10], regs->gprs[11]);
255 	buffer += sprintf(buffer, "           " FOURLONG,
256 			  regs->gprs[12], regs->gprs[13],
257 			  regs->gprs[14], regs->gprs[15]);
258 	buffer += sprintf(buffer, "User ACRS: %08x %08x %08x %08x\n",
259 			  task->thread.acrs[0], task->thread.acrs[1],
260 			  task->thread.acrs[2], task->thread.acrs[3]);
261 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
262 			  task->thread.acrs[4], task->thread.acrs[5],
263 			  task->thread.acrs[6], task->thread.acrs[7]);
264 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
265 			  task->thread.acrs[8], task->thread.acrs[9],
266 			  task->thread.acrs[10], task->thread.acrs[11]);
267 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
268 			  task->thread.acrs[12], task->thread.acrs[13],
269 			  task->thread.acrs[14], task->thread.acrs[15]);
270 	return buffer;
271 }
272 
273 DEFINE_SPINLOCK(die_lock);
274 
275 void die(const char * str, struct pt_regs * regs, long err)
276 {
277 	static int die_counter;
278 
279 	debug_stop_all();
280 	console_verbose();
281 	spin_lock_irq(&die_lock);
282 	bust_spinlocks(1);
283 	printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
284         show_regs(regs);
285 	bust_spinlocks(0);
286         spin_unlock_irq(&die_lock);
287 	if (in_interrupt())
288 		panic("Fatal exception in interrupt");
289 	if (panic_on_oops)
290 		panic("Fatal exception: panic_on_oops");
291         do_exit(SIGSEGV);
292 }
293 
294 static void inline
295 report_user_fault(long interruption_code, struct pt_regs *regs)
296 {
297 #if defined(CONFIG_SYSCTL)
298 	if (!sysctl_userprocess_debug)
299 		return;
300 #endif
301 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
302 	printk("User process fault: interruption code 0x%lX\n",
303 	       interruption_code);
304 	show_regs(regs);
305 #endif
306 }
307 
308 static void inline do_trap(long interruption_code, int signr, char *str,
309                            struct pt_regs *regs, siginfo_t *info)
310 {
311 	/*
312 	 * We got all needed information from the lowcore and can
313 	 * now safely switch on interrupts.
314 	 */
315         if (regs->psw.mask & PSW_MASK_PSTATE)
316 		local_irq_enable();
317 
318         if (regs->psw.mask & PSW_MASK_PSTATE) {
319                 struct task_struct *tsk = current;
320 
321                 tsk->thread.trap_no = interruption_code & 0xffff;
322 		force_sig_info(signr, info, tsk);
323 		report_user_fault(interruption_code, regs);
324         } else {
325                 const struct exception_table_entry *fixup;
326                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
327                 if (fixup)
328                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
329                 else
330                         die(str, regs, interruption_code);
331         }
332 }
333 
334 static inline void *get_check_address(struct pt_regs *regs)
335 {
336 	return (void *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
337 }
338 
339 void do_single_step(struct pt_regs *regs)
340 {
341 	if ((current->ptrace & PT_PTRACED) != 0)
342 		force_sig(SIGTRAP, current);
343 }
344 
345 asmlinkage void
346 default_trap_handler(struct pt_regs * regs, long interruption_code)
347 {
348         if (regs->psw.mask & PSW_MASK_PSTATE) {
349 		local_irq_enable();
350 		do_exit(SIGSEGV);
351 		report_user_fault(interruption_code, regs);
352 	} else
353 		die("Unknown program exception", regs, interruption_code);
354 }
355 
356 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
357 asmlinkage void name(struct pt_regs * regs, long interruption_code) \
358 { \
359         siginfo_t info; \
360         info.si_signo = signr; \
361         info.si_errno = 0; \
362         info.si_code = sicode; \
363         info.si_addr = (void *)siaddr; \
364         do_trap(interruption_code, signr, str, regs, &info); \
365 }
366 
367 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
368 	      ILL_ILLADR, get_check_address(regs))
369 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
370 	      ILL_ILLOPN, get_check_address(regs))
371 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
372 	      FPE_INTDIV, get_check_address(regs))
373 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
374 	      FPE_INTOVF, get_check_address(regs))
375 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
376 	      FPE_FLTOVF, get_check_address(regs))
377 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
378 	      FPE_FLTUND, get_check_address(regs))
379 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
380 	      FPE_FLTRES, get_check_address(regs))
381 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
382 	      FPE_FLTDIV, get_check_address(regs))
383 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
384 	      FPE_FLTINV, get_check_address(regs))
385 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
386 	      ILL_ILLOPN, get_check_address(regs))
387 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
388 	      ILL_PRVOPC, get_check_address(regs))
389 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
390 	      ILL_ILLOPN, get_check_address(regs))
391 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
392 	      ILL_ILLOPN, get_check_address(regs))
393 
394 static inline void
395 do_fp_trap(struct pt_regs *regs, void *location,
396            int fpc, long interruption_code)
397 {
398 	siginfo_t si;
399 
400 	si.si_signo = SIGFPE;
401 	si.si_errno = 0;
402 	si.si_addr = location;
403 	si.si_code = 0;
404 	/* FPC[2] is Data Exception Code */
405 	if ((fpc & 0x00000300) == 0) {
406 		/* bits 6 and 7 of DXC are 0 iff IEEE exception */
407 		if (fpc & 0x8000) /* invalid fp operation */
408 			si.si_code = FPE_FLTINV;
409 		else if (fpc & 0x4000) /* div by 0 */
410 			si.si_code = FPE_FLTDIV;
411 		else if (fpc & 0x2000) /* overflow */
412 			si.si_code = FPE_FLTOVF;
413 		else if (fpc & 0x1000) /* underflow */
414 			si.si_code = FPE_FLTUND;
415 		else if (fpc & 0x0800) /* inexact */
416 			si.si_code = FPE_FLTRES;
417 	}
418 	current->thread.ieee_instruction_pointer = (addr_t) location;
419 	do_trap(interruption_code, SIGFPE,
420 		"floating point exception", regs, &si);
421 }
422 
423 asmlinkage void illegal_op(struct pt_regs * regs, long interruption_code)
424 {
425 	siginfo_t info;
426         __u8 opcode[6];
427 	__u16 *location;
428 	int signal = 0;
429 
430 	location = (__u16 *) get_check_address(regs);
431 
432 	/*
433 	 * We got all needed information from the lowcore and can
434 	 * now safely switch on interrupts.
435 	 */
436 	if (regs->psw.mask & PSW_MASK_PSTATE)
437 		local_irq_enable();
438 
439 	if (regs->psw.mask & PSW_MASK_PSTATE) {
440 		get_user(*((__u16 *) opcode), (__u16 __user *) location);
441 		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
442 			if (current->ptrace & PT_PTRACED)
443 				force_sig(SIGTRAP, current);
444 			else
445 				signal = SIGILL;
446 #ifdef CONFIG_MATHEMU
447 		} else if (opcode[0] == 0xb3) {
448 			get_user(*((__u16 *) (opcode+2)), location+1);
449 			signal = math_emu_b3(opcode, regs);
450                 } else if (opcode[0] == 0xed) {
451 			get_user(*((__u32 *) (opcode+2)),
452 				 (__u32 *)(location+1));
453 			signal = math_emu_ed(opcode, regs);
454 		} else if (*((__u16 *) opcode) == 0xb299) {
455 			get_user(*((__u16 *) (opcode+2)), location+1);
456 			signal = math_emu_srnm(opcode, regs);
457 		} else if (*((__u16 *) opcode) == 0xb29c) {
458 			get_user(*((__u16 *) (opcode+2)), location+1);
459 			signal = math_emu_stfpc(opcode, regs);
460 		} else if (*((__u16 *) opcode) == 0xb29d) {
461 			get_user(*((__u16 *) (opcode+2)), location+1);
462 			signal = math_emu_lfpc(opcode, regs);
463 #endif
464 		} else
465 			signal = SIGILL;
466 	} else
467 		signal = SIGILL;
468 
469 #ifdef CONFIG_MATHEMU
470         if (signal == SIGFPE)
471 		do_fp_trap(regs, location,
472                            current->thread.fp_regs.fpc, interruption_code);
473         else if (signal == SIGSEGV) {
474 		info.si_signo = signal;
475 		info.si_errno = 0;
476 		info.si_code = SEGV_MAPERR;
477 		info.si_addr = (void *) location;
478 		do_trap(interruption_code, signal,
479 			"user address fault", regs, &info);
480 	} else
481 #endif
482         if (signal) {
483 		info.si_signo = signal;
484 		info.si_errno = 0;
485 		info.si_code = ILL_ILLOPC;
486 		info.si_addr = (void __user *) location;
487 		do_trap(interruption_code, signal,
488 			"illegal operation", regs, &info);
489 	}
490 }
491 
492 
493 #ifdef CONFIG_MATHEMU
494 asmlinkage void
495 specification_exception(struct pt_regs * regs, long interruption_code)
496 {
497         __u8 opcode[6];
498 	__u16 *location = NULL;
499 	int signal = 0;
500 
501 	location = (__u16 *) get_check_address(regs);
502 
503 	/*
504 	 * We got all needed information from the lowcore and can
505 	 * now safely switch on interrupts.
506 	 */
507         if (regs->psw.mask & PSW_MASK_PSTATE)
508 		local_irq_enable();
509 
510         if (regs->psw.mask & PSW_MASK_PSTATE) {
511 		get_user(*((__u16 *) opcode), location);
512 		switch (opcode[0]) {
513 		case 0x28: /* LDR Rx,Ry   */
514 			signal = math_emu_ldr(opcode);
515 			break;
516 		case 0x38: /* LER Rx,Ry   */
517 			signal = math_emu_ler(opcode);
518 			break;
519 		case 0x60: /* STD R,D(X,B) */
520 			get_user(*((__u16 *) (opcode+2)), location+1);
521 			signal = math_emu_std(opcode, regs);
522 			break;
523 		case 0x68: /* LD R,D(X,B) */
524 			get_user(*((__u16 *) (opcode+2)), location+1);
525 			signal = math_emu_ld(opcode, regs);
526 			break;
527 		case 0x70: /* STE R,D(X,B) */
528 			get_user(*((__u16 *) (opcode+2)), location+1);
529 			signal = math_emu_ste(opcode, regs);
530 			break;
531 		case 0x78: /* LE R,D(X,B) */
532 			get_user(*((__u16 *) (opcode+2)), location+1);
533 			signal = math_emu_le(opcode, regs);
534 			break;
535 		default:
536 			signal = SIGILL;
537 			break;
538                 }
539         } else
540 		signal = SIGILL;
541 
542         if (signal == SIGFPE)
543 		do_fp_trap(regs, location,
544                            current->thread.fp_regs.fpc, interruption_code);
545         else if (signal) {
546 		siginfo_t info;
547 		info.si_signo = signal;
548 		info.si_errno = 0;
549 		info.si_code = ILL_ILLOPN;
550 		info.si_addr = location;
551 		do_trap(interruption_code, signal,
552 			"specification exception", regs, &info);
553 	}
554 }
555 #else
556 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
557 	      ILL_ILLOPN, get_check_address(regs));
558 #endif
559 
560 asmlinkage void data_exception(struct pt_regs * regs, long interruption_code)
561 {
562 	__u16 *location;
563 	int signal = 0;
564 
565 	location = (__u16 *) get_check_address(regs);
566 
567 	/*
568 	 * We got all needed information from the lowcore and can
569 	 * now safely switch on interrupts.
570 	 */
571 	if (regs->psw.mask & PSW_MASK_PSTATE)
572 		local_irq_enable();
573 
574 	if (MACHINE_HAS_IEEE)
575 		__asm__ volatile ("stfpc %0\n\t"
576 				  : "=m" (current->thread.fp_regs.fpc));
577 
578 #ifdef CONFIG_MATHEMU
579         else if (regs->psw.mask & PSW_MASK_PSTATE) {
580         	__u8 opcode[6];
581 		get_user(*((__u16 *) opcode), location);
582 		switch (opcode[0]) {
583 		case 0x28: /* LDR Rx,Ry   */
584 			signal = math_emu_ldr(opcode);
585 			break;
586 		case 0x38: /* LER Rx,Ry   */
587 			signal = math_emu_ler(opcode);
588 			break;
589 		case 0x60: /* STD R,D(X,B) */
590 			get_user(*((__u16 *) (opcode+2)), location+1);
591 			signal = math_emu_std(opcode, regs);
592 			break;
593 		case 0x68: /* LD R,D(X,B) */
594 			get_user(*((__u16 *) (opcode+2)), location+1);
595 			signal = math_emu_ld(opcode, regs);
596 			break;
597 		case 0x70: /* STE R,D(X,B) */
598 			get_user(*((__u16 *) (opcode+2)), location+1);
599 			signal = math_emu_ste(opcode, regs);
600 			break;
601 		case 0x78: /* LE R,D(X,B) */
602 			get_user(*((__u16 *) (opcode+2)), location+1);
603 			signal = math_emu_le(opcode, regs);
604 			break;
605 		case 0xb3:
606 			get_user(*((__u16 *) (opcode+2)), location+1);
607 			signal = math_emu_b3(opcode, regs);
608 			break;
609                 case 0xed:
610 			get_user(*((__u32 *) (opcode+2)),
611 				 (__u32 *)(location+1));
612 			signal = math_emu_ed(opcode, regs);
613 			break;
614 	        case 0xb2:
615 			if (opcode[1] == 0x99) {
616 				get_user(*((__u16 *) (opcode+2)), location+1);
617 				signal = math_emu_srnm(opcode, regs);
618 			} else if (opcode[1] == 0x9c) {
619 				get_user(*((__u16 *) (opcode+2)), location+1);
620 				signal = math_emu_stfpc(opcode, regs);
621 			} else if (opcode[1] == 0x9d) {
622 				get_user(*((__u16 *) (opcode+2)), location+1);
623 				signal = math_emu_lfpc(opcode, regs);
624 			} else
625 				signal = SIGILL;
626 			break;
627 		default:
628 			signal = SIGILL;
629 			break;
630                 }
631         }
632 #endif
633 	if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
634 		signal = SIGFPE;
635 	else
636 		signal = SIGILL;
637         if (signal == SIGFPE)
638 		do_fp_trap(regs, location,
639                            current->thread.fp_regs.fpc, interruption_code);
640         else if (signal) {
641 		siginfo_t info;
642 		info.si_signo = signal;
643 		info.si_errno = 0;
644 		info.si_code = ILL_ILLOPN;
645 		info.si_addr = location;
646 		do_trap(interruption_code, signal,
647 			"data exception", regs, &info);
648 	}
649 }
650 
651 asmlinkage void space_switch_exception(struct pt_regs * regs, long int_code)
652 {
653         siginfo_t info;
654 
655 	/* Set user psw back to home space mode. */
656 	if (regs->psw.mask & PSW_MASK_PSTATE)
657 		regs->psw.mask |= PSW_ASC_HOME;
658 	/* Send SIGILL. */
659         info.si_signo = SIGILL;
660         info.si_errno = 0;
661         info.si_code = ILL_PRVOPC;
662         info.si_addr = get_check_address(regs);
663         do_trap(int_code, SIGILL, "space switch event", regs, &info);
664 }
665 
666 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
667 {
668 	bust_spinlocks(1);
669 	printk("Kernel stack overflow.\n");
670 	show_regs(regs);
671 	bust_spinlocks(0);
672 	panic("Corrupt kernel stack, can't continue.");
673 }
674 
675 /* init is done in lowcore.S and head.S */
676 
677 void __init trap_init(void)
678 {
679         int i;
680 
681         for (i = 0; i < 128; i++)
682           pgm_check_table[i] = &default_trap_handler;
683         pgm_check_table[1] = &illegal_op;
684         pgm_check_table[2] = &privileged_op;
685         pgm_check_table[3] = &execute_exception;
686         pgm_check_table[4] = &do_protection_exception;
687         pgm_check_table[5] = &addressing_exception;
688         pgm_check_table[6] = &specification_exception;
689         pgm_check_table[7] = &data_exception;
690         pgm_check_table[8] = &overflow_exception;
691         pgm_check_table[9] = &divide_exception;
692         pgm_check_table[0x0A] = &overflow_exception;
693         pgm_check_table[0x0B] = &divide_exception;
694         pgm_check_table[0x0C] = &hfp_overflow_exception;
695         pgm_check_table[0x0D] = &hfp_underflow_exception;
696         pgm_check_table[0x0E] = &hfp_significance_exception;
697         pgm_check_table[0x0F] = &hfp_divide_exception;
698         pgm_check_table[0x10] = &do_dat_exception;
699         pgm_check_table[0x11] = &do_dat_exception;
700         pgm_check_table[0x12] = &translation_exception;
701         pgm_check_table[0x13] = &special_op_exception;
702 #ifdef CONFIG_64BIT
703         pgm_check_table[0x38] = &do_dat_exception;
704 	pgm_check_table[0x39] = &do_dat_exception;
705 	pgm_check_table[0x3A] = &do_dat_exception;
706         pgm_check_table[0x3B] = &do_dat_exception;
707 #endif /* CONFIG_64BIT */
708         pgm_check_table[0x15] = &operand_exception;
709         pgm_check_table[0x1C] = &space_switch_exception;
710         pgm_check_table[0x1D] = &hfp_sqrt_exception;
711 	pgm_check_table[0x40] = &do_monitor_call;
712 
713 	if (MACHINE_IS_VM) {
714 #ifdef CONFIG_PFAULT
715 		/*
716 		 * Try to get pfault pseudo page faults going.
717 		 */
718 		if (register_early_external_interrupt(0x2603, pfault_interrupt,
719 						      &ext_int_pfault) != 0)
720 			panic("Couldn't request external interrupt 0x2603");
721 
722 		if (pfault_init() == 0)
723 			return;
724 
725 		/* Tough luck, no pfault. */
726 		unregister_early_external_interrupt(0x2603, pfault_interrupt,
727 						    &ext_int_pfault);
728 #endif
729 	}
730 }
731