xref: /linux/arch/s390/kernel/traps.c (revision 5e8d780d745c1619aba81fe7166c5a4b5cad2b84)
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/config.h>
18 #include <linux/sched.h>
19 #include <linux/kernel.h>
20 #include <linux/string.h>
21 #include <linux/errno.h>
22 #include <linux/ptrace.h>
23 #include <linux/timer.h>
24 #include <linux/mm.h>
25 #include <linux/smp.h>
26 #include <linux/smp_lock.h>
27 #include <linux/init.h>
28 #include <linux/interrupt.h>
29 #include <linux/delay.h>
30 #include <linux/module.h>
31 #include <linux/kallsyms.h>
32 #include <linux/reboot.h>
33 
34 #include <asm/system.h>
35 #include <asm/uaccess.h>
36 #include <asm/io.h>
37 #include <asm/atomic.h>
38 #include <asm/mathemu.h>
39 #include <asm/cpcmd.h>
40 #include <asm/s390_ext.h>
41 #include <asm/lowcore.h>
42 #include <asm/debug.h>
43 
44 /* Called from entry.S only */
45 extern void handle_per_exception(struct pt_regs *regs);
46 
47 typedef void pgm_check_handler_t(struct pt_regs *, long);
48 pgm_check_handler_t *pgm_check_table[128];
49 
50 #ifdef CONFIG_SYSCTL
51 #ifdef CONFIG_PROCESS_DEBUG
52 int sysctl_userprocess_debug = 1;
53 #else
54 int sysctl_userprocess_debug = 0;
55 #endif
56 #endif
57 
58 extern pgm_check_handler_t do_protection_exception;
59 extern pgm_check_handler_t do_dat_exception;
60 #ifdef CONFIG_PFAULT
61 extern int pfault_init(void);
62 extern void pfault_fini(void);
63 extern void pfault_interrupt(struct pt_regs *regs, __u16 error_code);
64 static ext_int_info_t ext_int_pfault;
65 #endif
66 extern pgm_check_handler_t do_monitor_call;
67 
68 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
69 
70 #ifndef CONFIG_64BIT
71 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
72 static int kstack_depth_to_print = 12;
73 #else /* CONFIG_64BIT */
74 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
75 static int kstack_depth_to_print = 20;
76 #endif /* CONFIG_64BIT */
77 
78 /*
79  * For show_trace we have tree different stack to consider:
80  *   - the panic stack which is used if the kernel stack has overflown
81  *   - the asynchronous interrupt stack (cpu related)
82  *   - the synchronous kernel stack (process related)
83  * The stack trace can start at any of the three stack and can potentially
84  * touch all of them. The order is: panic stack, async stack, sync stack.
85  */
86 static unsigned long
87 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
88 {
89 	struct stack_frame *sf;
90 	struct pt_regs *regs;
91 
92 	while (1) {
93 		sp = sp & PSW_ADDR_INSN;
94 		if (sp < low || sp > high - sizeof(*sf))
95 			return sp;
96 		sf = (struct stack_frame *) sp;
97 		printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
98 		print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
99 		/* Follow the backchain. */
100 		while (1) {
101 			low = sp;
102 			sp = sf->back_chain & PSW_ADDR_INSN;
103 			if (!sp)
104 				break;
105 			if (sp <= low || sp > high - sizeof(*sf))
106 				return sp;
107 			sf = (struct stack_frame *) sp;
108 			printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
109 			print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
110 		}
111 		/* Zero backchain detected, check for interrupt frame. */
112 		sp = (unsigned long) (sf + 1);
113 		if (sp <= low || sp > high - sizeof(*regs))
114 			return sp;
115 		regs = (struct pt_regs *) sp;
116 		printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
117 		print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
118 		low = sp;
119 		sp = regs->gprs[15];
120 	}
121 }
122 
123 void show_trace(struct task_struct *task, unsigned long * stack)
124 {
125 	register unsigned long __r15 asm ("15");
126 	unsigned long sp;
127 
128 	sp = (unsigned long) stack;
129 	if (!sp)
130 		sp = task ? task->thread.ksp : __r15;
131 	printk("Call Trace:\n");
132 #ifdef CONFIG_CHECK_STACK
133 	sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
134 			  S390_lowcore.panic_stack);
135 #endif
136 	sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
137 			  S390_lowcore.async_stack);
138 	if (task)
139 		__show_trace(sp, (unsigned long) task_stack_page(task),
140 			     (unsigned long) task_stack_page(task) + THREAD_SIZE);
141 	else
142 		__show_trace(sp, S390_lowcore.thread_info,
143 			     S390_lowcore.thread_info + THREAD_SIZE);
144 	printk("\n");
145 }
146 
147 void show_stack(struct task_struct *task, unsigned long *sp)
148 {
149 	register unsigned long * __r15 asm ("15");
150 	unsigned long *stack;
151 	int i;
152 
153 	if (!sp)
154 		stack = task ? (unsigned long *) task->thread.ksp : __r15;
155 	else
156 		stack = sp;
157 
158 	for (i = 0; i < kstack_depth_to_print; i++) {
159 		if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
160 			break;
161 		if (i && ((i * sizeof (long) % 32) == 0))
162 			printk("\n       ");
163 		printk("%p ", (void *)*stack++);
164 	}
165 	printk("\n");
166 	show_trace(task, sp);
167 }
168 
169 /*
170  * The architecture-independent dump_stack generator
171  */
172 void dump_stack(void)
173 {
174 	show_stack(0, 0);
175 }
176 
177 EXPORT_SYMBOL(dump_stack);
178 
179 void show_registers(struct pt_regs *regs)
180 {
181 	mm_segment_t old_fs;
182 	char *mode;
183 	int i;
184 
185 	mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
186 	printk("%s PSW : %p %p",
187 	       mode, (void *) regs->psw.mask,
188 	       (void *) regs->psw.addr);
189 	print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
190 	printk("%s GPRS: " FOURLONG, mode,
191 	       regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
192 	printk("           " FOURLONG,
193 	       regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
194 	printk("           " FOURLONG,
195 	       regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
196 	printk("           " FOURLONG,
197 	       regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
198 
199 #if 0
200 	/* FIXME: this isn't needed any more but it changes the ksymoops
201 	 * input. To remove or not to remove ... */
202 	save_access_regs(regs->acrs);
203 	printk("%s ACRS: %08x %08x %08x %08x\n", mode,
204 	       regs->acrs[0], regs->acrs[1], regs->acrs[2], regs->acrs[3]);
205 	printk("           %08x %08x %08x %08x\n",
206 	       regs->acrs[4], regs->acrs[5], regs->acrs[6], regs->acrs[7]);
207 	printk("           %08x %08x %08x %08x\n",
208 	       regs->acrs[8], regs->acrs[9], regs->acrs[10], regs->acrs[11]);
209 	printk("           %08x %08x %08x %08x\n",
210 	       regs->acrs[12], regs->acrs[13], regs->acrs[14], regs->acrs[15]);
211 #endif
212 
213 	/*
214 	 * Print the first 20 byte of the instruction stream at the
215 	 * time of the fault.
216 	 */
217 	old_fs = get_fs();
218 	if (regs->psw.mask & PSW_MASK_PSTATE)
219 		set_fs(USER_DS);
220 	else
221 		set_fs(KERNEL_DS);
222 	printk("%s Code: ", mode);
223 	for (i = 0; i < 20; i++) {
224 		unsigned char c;
225 		if (__get_user(c, (char __user *)(regs->psw.addr + i))) {
226 			printk(" Bad PSW.");
227 			break;
228 		}
229 		printk("%02x ", c);
230 	}
231 	set_fs(old_fs);
232 
233 	printk("\n");
234 }
235 
236 /* This is called from fs/proc/array.c */
237 char *task_show_regs(struct task_struct *task, char *buffer)
238 {
239 	struct pt_regs *regs;
240 
241 	regs = task_pt_regs(task);
242 	buffer += sprintf(buffer, "task: %p, ksp: %p\n",
243 		       task, (void *)task->thread.ksp);
244 	buffer += sprintf(buffer, "User PSW : %p %p\n",
245 		       (void *) regs->psw.mask, (void *)regs->psw.addr);
246 
247 	buffer += sprintf(buffer, "User GPRS: " FOURLONG,
248 			  regs->gprs[0], regs->gprs[1],
249 			  regs->gprs[2], regs->gprs[3]);
250 	buffer += sprintf(buffer, "           " FOURLONG,
251 			  regs->gprs[4], regs->gprs[5],
252 			  regs->gprs[6], regs->gprs[7]);
253 	buffer += sprintf(buffer, "           " FOURLONG,
254 			  regs->gprs[8], regs->gprs[9],
255 			  regs->gprs[10], regs->gprs[11]);
256 	buffer += sprintf(buffer, "           " FOURLONG,
257 			  regs->gprs[12], regs->gprs[13],
258 			  regs->gprs[14], regs->gprs[15]);
259 	buffer += sprintf(buffer, "User ACRS: %08x %08x %08x %08x\n",
260 			  task->thread.acrs[0], task->thread.acrs[1],
261 			  task->thread.acrs[2], task->thread.acrs[3]);
262 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
263 			  task->thread.acrs[4], task->thread.acrs[5],
264 			  task->thread.acrs[6], task->thread.acrs[7]);
265 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
266 			  task->thread.acrs[8], task->thread.acrs[9],
267 			  task->thread.acrs[10], task->thread.acrs[11]);
268 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
269 			  task->thread.acrs[12], task->thread.acrs[13],
270 			  task->thread.acrs[14], task->thread.acrs[15]);
271 	return buffer;
272 }
273 
274 DEFINE_SPINLOCK(die_lock);
275 
276 void die(const char * str, struct pt_regs * regs, long err)
277 {
278 	static int die_counter;
279 
280 	debug_stop_all();
281 	console_verbose();
282 	spin_lock_irq(&die_lock);
283 	bust_spinlocks(1);
284 	printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
285         show_regs(regs);
286 	bust_spinlocks(0);
287         spin_unlock_irq(&die_lock);
288 	if (in_interrupt())
289 		panic("Fatal exception in interrupt");
290 	if (panic_on_oops)
291 		panic("Fatal exception: panic_on_oops");
292         do_exit(SIGSEGV);
293 }
294 
295 static void inline
296 report_user_fault(long interruption_code, struct pt_regs *regs)
297 {
298 #if defined(CONFIG_SYSCTL)
299 	if (!sysctl_userprocess_debug)
300 		return;
301 #endif
302 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
303 	printk("User process fault: interruption code 0x%lX\n",
304 	       interruption_code);
305 	show_regs(regs);
306 #endif
307 }
308 
309 static void inline do_trap(long interruption_code, int signr, char *str,
310                            struct pt_regs *regs, siginfo_t *info)
311 {
312 	/*
313 	 * We got all needed information from the lowcore and can
314 	 * now safely switch on interrupts.
315 	 */
316         if (regs->psw.mask & PSW_MASK_PSTATE)
317 		local_irq_enable();
318 
319         if (regs->psw.mask & PSW_MASK_PSTATE) {
320                 struct task_struct *tsk = current;
321 
322                 tsk->thread.trap_no = interruption_code & 0xffff;
323 		force_sig_info(signr, info, tsk);
324 		report_user_fault(interruption_code, regs);
325         } else {
326                 const struct exception_table_entry *fixup;
327                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
328                 if (fixup)
329                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
330                 else
331                         die(str, regs, interruption_code);
332         }
333 }
334 
335 static inline void *get_check_address(struct pt_regs *regs)
336 {
337 	return (void *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
338 }
339 
340 void do_single_step(struct pt_regs *regs)
341 {
342 	if ((current->ptrace & PT_PTRACED) != 0)
343 		force_sig(SIGTRAP, current);
344 }
345 
346 asmlinkage void
347 default_trap_handler(struct pt_regs * regs, long interruption_code)
348 {
349         if (regs->psw.mask & PSW_MASK_PSTATE) {
350 		local_irq_enable();
351 		do_exit(SIGSEGV);
352 		report_user_fault(interruption_code, regs);
353 	} else
354 		die("Unknown program exception", regs, interruption_code);
355 }
356 
357 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
358 asmlinkage void name(struct pt_regs * regs, long interruption_code) \
359 { \
360         siginfo_t info; \
361         info.si_signo = signr; \
362         info.si_errno = 0; \
363         info.si_code = sicode; \
364         info.si_addr = (void *)siaddr; \
365         do_trap(interruption_code, signr, str, regs, &info); \
366 }
367 
368 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
369 	      ILL_ILLADR, get_check_address(regs))
370 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
371 	      ILL_ILLOPN, get_check_address(regs))
372 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
373 	      FPE_INTDIV, get_check_address(regs))
374 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
375 	      FPE_INTOVF, get_check_address(regs))
376 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
377 	      FPE_FLTOVF, get_check_address(regs))
378 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
379 	      FPE_FLTUND, get_check_address(regs))
380 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
381 	      FPE_FLTRES, get_check_address(regs))
382 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
383 	      FPE_FLTDIV, get_check_address(regs))
384 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
385 	      FPE_FLTINV, get_check_address(regs))
386 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
387 	      ILL_ILLOPN, get_check_address(regs))
388 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
389 	      ILL_PRVOPC, get_check_address(regs))
390 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
391 	      ILL_ILLOPN, get_check_address(regs))
392 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
393 	      ILL_ILLOPN, get_check_address(regs))
394 
395 static inline void
396 do_fp_trap(struct pt_regs *regs, void *location,
397            int fpc, long interruption_code)
398 {
399 	siginfo_t si;
400 
401 	si.si_signo = SIGFPE;
402 	si.si_errno = 0;
403 	si.si_addr = location;
404 	si.si_code = 0;
405 	/* FPC[2] is Data Exception Code */
406 	if ((fpc & 0x00000300) == 0) {
407 		/* bits 6 and 7 of DXC are 0 iff IEEE exception */
408 		if (fpc & 0x8000) /* invalid fp operation */
409 			si.si_code = FPE_FLTINV;
410 		else if (fpc & 0x4000) /* div by 0 */
411 			si.si_code = FPE_FLTDIV;
412 		else if (fpc & 0x2000) /* overflow */
413 			si.si_code = FPE_FLTOVF;
414 		else if (fpc & 0x1000) /* underflow */
415 			si.si_code = FPE_FLTUND;
416 		else if (fpc & 0x0800) /* inexact */
417 			si.si_code = FPE_FLTRES;
418 	}
419 	current->thread.ieee_instruction_pointer = (addr_t) location;
420 	do_trap(interruption_code, SIGFPE,
421 		"floating point exception", regs, &si);
422 }
423 
424 asmlinkage void illegal_op(struct pt_regs * regs, long interruption_code)
425 {
426 	siginfo_t info;
427         __u8 opcode[6];
428 	__u16 *location;
429 	int signal = 0;
430 
431 	location = (__u16 *) get_check_address(regs);
432 
433 	/*
434 	 * We got all needed information from the lowcore and can
435 	 * now safely switch on interrupts.
436 	 */
437 	if (regs->psw.mask & PSW_MASK_PSTATE)
438 		local_irq_enable();
439 
440 	if (regs->psw.mask & PSW_MASK_PSTATE) {
441 		get_user(*((__u16 *) opcode), (__u16 __user *) location);
442 		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
443 			if (current->ptrace & PT_PTRACED)
444 				force_sig(SIGTRAP, current);
445 			else
446 				signal = SIGILL;
447 #ifdef CONFIG_MATHEMU
448 		} else if (opcode[0] == 0xb3) {
449 			get_user(*((__u16 *) (opcode+2)), location+1);
450 			signal = math_emu_b3(opcode, regs);
451                 } else if (opcode[0] == 0xed) {
452 			get_user(*((__u32 *) (opcode+2)),
453 				 (__u32 *)(location+1));
454 			signal = math_emu_ed(opcode, regs);
455 		} else if (*((__u16 *) opcode) == 0xb299) {
456 			get_user(*((__u16 *) (opcode+2)), location+1);
457 			signal = math_emu_srnm(opcode, regs);
458 		} else if (*((__u16 *) opcode) == 0xb29c) {
459 			get_user(*((__u16 *) (opcode+2)), location+1);
460 			signal = math_emu_stfpc(opcode, regs);
461 		} else if (*((__u16 *) opcode) == 0xb29d) {
462 			get_user(*((__u16 *) (opcode+2)), location+1);
463 			signal = math_emu_lfpc(opcode, regs);
464 #endif
465 		} else
466 			signal = SIGILL;
467 	} else
468 		signal = SIGILL;
469 
470 #ifdef CONFIG_MATHEMU
471         if (signal == SIGFPE)
472 		do_fp_trap(regs, location,
473                            current->thread.fp_regs.fpc, interruption_code);
474         else if (signal == SIGSEGV) {
475 		info.si_signo = signal;
476 		info.si_errno = 0;
477 		info.si_code = SEGV_MAPERR;
478 		info.si_addr = (void *) location;
479 		do_trap(interruption_code, signal,
480 			"user address fault", regs, &info);
481 	} else
482 #endif
483         if (signal) {
484 		info.si_signo = signal;
485 		info.si_errno = 0;
486 		info.si_code = ILL_ILLOPC;
487 		info.si_addr = (void __user *) location;
488 		do_trap(interruption_code, signal,
489 			"illegal operation", regs, &info);
490 	}
491 }
492 
493 
494 #ifdef CONFIG_MATHEMU
495 asmlinkage void
496 specification_exception(struct pt_regs * regs, long interruption_code)
497 {
498         __u8 opcode[6];
499 	__u16 *location = NULL;
500 	int signal = 0;
501 
502 	location = (__u16 *) get_check_address(regs);
503 
504 	/*
505 	 * We got all needed information from the lowcore and can
506 	 * now safely switch on interrupts.
507 	 */
508         if (regs->psw.mask & PSW_MASK_PSTATE)
509 		local_irq_enable();
510 
511         if (regs->psw.mask & PSW_MASK_PSTATE) {
512 		get_user(*((__u16 *) opcode), location);
513 		switch (opcode[0]) {
514 		case 0x28: /* LDR Rx,Ry   */
515 			signal = math_emu_ldr(opcode);
516 			break;
517 		case 0x38: /* LER Rx,Ry   */
518 			signal = math_emu_ler(opcode);
519 			break;
520 		case 0x60: /* STD R,D(X,B) */
521 			get_user(*((__u16 *) (opcode+2)), location+1);
522 			signal = math_emu_std(opcode, regs);
523 			break;
524 		case 0x68: /* LD R,D(X,B) */
525 			get_user(*((__u16 *) (opcode+2)), location+1);
526 			signal = math_emu_ld(opcode, regs);
527 			break;
528 		case 0x70: /* STE R,D(X,B) */
529 			get_user(*((__u16 *) (opcode+2)), location+1);
530 			signal = math_emu_ste(opcode, regs);
531 			break;
532 		case 0x78: /* LE R,D(X,B) */
533 			get_user(*((__u16 *) (opcode+2)), location+1);
534 			signal = math_emu_le(opcode, regs);
535 			break;
536 		default:
537 			signal = SIGILL;
538 			break;
539                 }
540         } else
541 		signal = SIGILL;
542 
543         if (signal == SIGFPE)
544 		do_fp_trap(regs, location,
545                            current->thread.fp_regs.fpc, interruption_code);
546         else if (signal) {
547 		siginfo_t info;
548 		info.si_signo = signal;
549 		info.si_errno = 0;
550 		info.si_code = ILL_ILLOPN;
551 		info.si_addr = location;
552 		do_trap(interruption_code, signal,
553 			"specification exception", regs, &info);
554 	}
555 }
556 #else
557 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
558 	      ILL_ILLOPN, get_check_address(regs));
559 #endif
560 
561 asmlinkage void data_exception(struct pt_regs * regs, long interruption_code)
562 {
563 	__u16 *location;
564 	int signal = 0;
565 
566 	location = (__u16 *) get_check_address(regs);
567 
568 	/*
569 	 * We got all needed information from the lowcore and can
570 	 * now safely switch on interrupts.
571 	 */
572 	if (regs->psw.mask & PSW_MASK_PSTATE)
573 		local_irq_enable();
574 
575 	if (MACHINE_HAS_IEEE)
576 		__asm__ volatile ("stfpc %0\n\t"
577 				  : "=m" (current->thread.fp_regs.fpc));
578 
579 #ifdef CONFIG_MATHEMU
580         else if (regs->psw.mask & PSW_MASK_PSTATE) {
581         	__u8 opcode[6];
582 		get_user(*((__u16 *) opcode), location);
583 		switch (opcode[0]) {
584 		case 0x28: /* LDR Rx,Ry   */
585 			signal = math_emu_ldr(opcode);
586 			break;
587 		case 0x38: /* LER Rx,Ry   */
588 			signal = math_emu_ler(opcode);
589 			break;
590 		case 0x60: /* STD R,D(X,B) */
591 			get_user(*((__u16 *) (opcode+2)), location+1);
592 			signal = math_emu_std(opcode, regs);
593 			break;
594 		case 0x68: /* LD R,D(X,B) */
595 			get_user(*((__u16 *) (opcode+2)), location+1);
596 			signal = math_emu_ld(opcode, regs);
597 			break;
598 		case 0x70: /* STE R,D(X,B) */
599 			get_user(*((__u16 *) (opcode+2)), location+1);
600 			signal = math_emu_ste(opcode, regs);
601 			break;
602 		case 0x78: /* LE R,D(X,B) */
603 			get_user(*((__u16 *) (opcode+2)), location+1);
604 			signal = math_emu_le(opcode, regs);
605 			break;
606 		case 0xb3:
607 			get_user(*((__u16 *) (opcode+2)), location+1);
608 			signal = math_emu_b3(opcode, regs);
609 			break;
610                 case 0xed:
611 			get_user(*((__u32 *) (opcode+2)),
612 				 (__u32 *)(location+1));
613 			signal = math_emu_ed(opcode, regs);
614 			break;
615 	        case 0xb2:
616 			if (opcode[1] == 0x99) {
617 				get_user(*((__u16 *) (opcode+2)), location+1);
618 				signal = math_emu_srnm(opcode, regs);
619 			} else if (opcode[1] == 0x9c) {
620 				get_user(*((__u16 *) (opcode+2)), location+1);
621 				signal = math_emu_stfpc(opcode, regs);
622 			} else if (opcode[1] == 0x9d) {
623 				get_user(*((__u16 *) (opcode+2)), location+1);
624 				signal = math_emu_lfpc(opcode, regs);
625 			} else
626 				signal = SIGILL;
627 			break;
628 		default:
629 			signal = SIGILL;
630 			break;
631                 }
632         }
633 #endif
634 	if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
635 		signal = SIGFPE;
636 	else
637 		signal = SIGILL;
638         if (signal == SIGFPE)
639 		do_fp_trap(regs, location,
640                            current->thread.fp_regs.fpc, interruption_code);
641         else if (signal) {
642 		siginfo_t info;
643 		info.si_signo = signal;
644 		info.si_errno = 0;
645 		info.si_code = ILL_ILLOPN;
646 		info.si_addr = location;
647 		do_trap(interruption_code, signal,
648 			"data exception", regs, &info);
649 	}
650 }
651 
652 asmlinkage void space_switch_exception(struct pt_regs * regs, long int_code)
653 {
654         siginfo_t info;
655 
656 	/* Set user psw back to home space mode. */
657 	if (regs->psw.mask & PSW_MASK_PSTATE)
658 		regs->psw.mask |= PSW_ASC_HOME;
659 	/* Send SIGILL. */
660         info.si_signo = SIGILL;
661         info.si_errno = 0;
662         info.si_code = ILL_PRVOPC;
663         info.si_addr = get_check_address(regs);
664         do_trap(int_code, SIGILL, "space switch event", regs, &info);
665 }
666 
667 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
668 {
669 	bust_spinlocks(1);
670 	printk("Kernel stack overflow.\n");
671 	show_regs(regs);
672 	bust_spinlocks(0);
673 	panic("Corrupt kernel stack, can't continue.");
674 }
675 
676 /* init is done in lowcore.S and head.S */
677 
678 void __init trap_init(void)
679 {
680         int i;
681 
682         for (i = 0; i < 128; i++)
683           pgm_check_table[i] = &default_trap_handler;
684         pgm_check_table[1] = &illegal_op;
685         pgm_check_table[2] = &privileged_op;
686         pgm_check_table[3] = &execute_exception;
687         pgm_check_table[4] = &do_protection_exception;
688         pgm_check_table[5] = &addressing_exception;
689         pgm_check_table[6] = &specification_exception;
690         pgm_check_table[7] = &data_exception;
691         pgm_check_table[8] = &overflow_exception;
692         pgm_check_table[9] = &divide_exception;
693         pgm_check_table[0x0A] = &overflow_exception;
694         pgm_check_table[0x0B] = &divide_exception;
695         pgm_check_table[0x0C] = &hfp_overflow_exception;
696         pgm_check_table[0x0D] = &hfp_underflow_exception;
697         pgm_check_table[0x0E] = &hfp_significance_exception;
698         pgm_check_table[0x0F] = &hfp_divide_exception;
699         pgm_check_table[0x10] = &do_dat_exception;
700         pgm_check_table[0x11] = &do_dat_exception;
701         pgm_check_table[0x12] = &translation_exception;
702         pgm_check_table[0x13] = &special_op_exception;
703 #ifdef CONFIG_64BIT
704         pgm_check_table[0x38] = &do_dat_exception;
705 	pgm_check_table[0x39] = &do_dat_exception;
706 	pgm_check_table[0x3A] = &do_dat_exception;
707         pgm_check_table[0x3B] = &do_dat_exception;
708 #endif /* CONFIG_64BIT */
709         pgm_check_table[0x15] = &operand_exception;
710         pgm_check_table[0x1C] = &space_switch_exception;
711         pgm_check_table[0x1D] = &hfp_sqrt_exception;
712 	pgm_check_table[0x40] = &do_monitor_call;
713 
714 	if (MACHINE_IS_VM) {
715 #ifdef CONFIG_PFAULT
716 		/*
717 		 * Try to get pfault pseudo page faults going.
718 		 */
719 		if (register_early_external_interrupt(0x2603, pfault_interrupt,
720 						      &ext_int_pfault) != 0)
721 			panic("Couldn't request external interrupt 0x2603");
722 
723 		if (pfault_init() == 0)
724 			return;
725 
726 		/* Tough luck, no pfault. */
727 		unregister_early_external_interrupt(0x2603, pfault_interrupt,
728 						    &ext_int_pfault);
729 #endif
730 	}
731 }
732