xref: /linux/arch/s390/kernel/traps.c (revision 13abf8130139c2ccd4962a7e5a8902be5e6cb5a7)
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 extern pgm_check_handler_t do_pseudo_page_fault;
61 #ifdef CONFIG_PFAULT
62 extern int pfault_init(void);
63 extern void pfault_fini(void);
64 extern void pfault_interrupt(struct pt_regs *regs, __u16 error_code);
65 static ext_int_info_t ext_int_pfault;
66 #endif
67 extern pgm_check_handler_t do_monitor_call;
68 
69 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
70 
71 #ifndef CONFIG_ARCH_S390X
72 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
73 static int kstack_depth_to_print = 12;
74 #else /* CONFIG_ARCH_S390X */
75 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
76 static int kstack_depth_to_print = 20;
77 #endif /* CONFIG_ARCH_S390X */
78 
79 /*
80  * For show_trace we have tree different stack to consider:
81  *   - the panic stack which is used if the kernel stack has overflown
82  *   - the asynchronous interrupt stack (cpu related)
83  *   - the synchronous kernel stack (process related)
84  * The stack trace can start at any of the three stack and can potentially
85  * touch all of them. The order is: panic stack, async stack, sync stack.
86  */
87 static unsigned long
88 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
89 {
90 	struct stack_frame *sf;
91 	struct pt_regs *regs;
92 
93 	while (1) {
94 		sp = sp & PSW_ADDR_INSN;
95 		if (sp < low || sp > high - sizeof(*sf))
96 			return sp;
97 		sf = (struct stack_frame *) sp;
98 		printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
99 		print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
100 		/* Follow the backchain. */
101 		while (1) {
102 			low = sp;
103 			sp = sf->back_chain & PSW_ADDR_INSN;
104 			if (!sp)
105 				break;
106 			if (sp <= low || sp > high - sizeof(*sf))
107 				return sp;
108 			sf = (struct stack_frame *) sp;
109 			printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
110 			print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
111 		}
112 		/* Zero backchain detected, check for interrupt frame. */
113 		sp = (unsigned long) (sf + 1);
114 		if (sp <= low || sp > high - sizeof(*regs))
115 			return sp;
116 		regs = (struct pt_regs *) sp;
117 		printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
118 		print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
119 		low = sp;
120 		sp = regs->gprs[15];
121 	}
122 }
123 
124 void show_trace(struct task_struct *task, unsigned long * stack)
125 {
126 	register unsigned long __r15 asm ("15");
127 	unsigned long sp;
128 
129 	sp = (unsigned long) stack;
130 	if (!sp)
131 		sp = task ? task->thread.ksp : __r15;
132 	printk("Call Trace:\n");
133 #ifdef CONFIG_CHECK_STACK
134 	sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
135 			  S390_lowcore.panic_stack);
136 #endif
137 	sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
138 			  S390_lowcore.async_stack);
139 	if (task)
140 		__show_trace(sp, (unsigned long) task->thread_info,
141 			     (unsigned long) task->thread_info + THREAD_SIZE);
142 	else
143 		__show_trace(sp, S390_lowcore.thread_info,
144 			     S390_lowcore.thread_info + THREAD_SIZE);
145 	printk("\n");
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 	// debugging aid: "show_stack(NULL);" prints the
155 	// back trace for this cpu.
156 
157 	if (!sp)
158 		sp = task ? (unsigned long *) task->thread.ksp : __r15;
159 
160 	stack = sp;
161 	for (i = 0; i < kstack_depth_to_print; i++) {
162 		if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
163 			break;
164 		if (i && ((i * sizeof (long) % 32) == 0))
165 			printk("\n       ");
166 		printk("%p ", (void *)*stack++);
167 	}
168 	printk("\n");
169 	show_trace(task, sp);
170 }
171 
172 /*
173  * The architecture-independent dump_stack generator
174  */
175 void dump_stack(void)
176 {
177 	show_stack(0, 0);
178 }
179 
180 EXPORT_SYMBOL(dump_stack);
181 
182 void show_registers(struct pt_regs *regs)
183 {
184 	mm_segment_t old_fs;
185 	char *mode;
186 	int i;
187 
188 	mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
189 	printk("%s PSW : %p %p",
190 	       mode, (void *) regs->psw.mask,
191 	       (void *) regs->psw.addr);
192 	print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
193 	printk("%s GPRS: " FOURLONG, mode,
194 	       regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
195 	printk("           " FOURLONG,
196 	       regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
197 	printk("           " FOURLONG,
198 	       regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
199 	printk("           " FOURLONG,
200 	       regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
201 
202 #if 0
203 	/* FIXME: this isn't needed any more but it changes the ksymoops
204 	 * input. To remove or not to remove ... */
205 	save_access_regs(regs->acrs);
206 	printk("%s ACRS: %08x %08x %08x %08x\n", mode,
207 	       regs->acrs[0], regs->acrs[1], regs->acrs[2], regs->acrs[3]);
208 	printk("           %08x %08x %08x %08x\n",
209 	       regs->acrs[4], regs->acrs[5], regs->acrs[6], regs->acrs[7]);
210 	printk("           %08x %08x %08x %08x\n",
211 	       regs->acrs[8], regs->acrs[9], regs->acrs[10], regs->acrs[11]);
212 	printk("           %08x %08x %08x %08x\n",
213 	       regs->acrs[12], regs->acrs[13], regs->acrs[14], regs->acrs[15]);
214 #endif
215 
216 	/*
217 	 * Print the first 20 byte of the instruction stream at the
218 	 * time of the fault.
219 	 */
220 	old_fs = get_fs();
221 	if (regs->psw.mask & PSW_MASK_PSTATE)
222 		set_fs(USER_DS);
223 	else
224 		set_fs(KERNEL_DS);
225 	printk("%s Code: ", mode);
226 	for (i = 0; i < 20; i++) {
227 		unsigned char c;
228 		if (__get_user(c, (char __user *)(regs->psw.addr + i))) {
229 			printk(" Bad PSW.");
230 			break;
231 		}
232 		printk("%02x ", c);
233 	}
234 	set_fs(old_fs);
235 
236 	printk("\n");
237 }
238 
239 /* This is called from fs/proc/array.c */
240 char *task_show_regs(struct task_struct *task, char *buffer)
241 {
242 	struct pt_regs *regs;
243 
244 	regs = __KSTK_PTREGS(task);
245 	buffer += sprintf(buffer, "task: %p, ksp: %p\n",
246 		       task, (void *)task->thread.ksp);
247 	buffer += sprintf(buffer, "User PSW : %p %p\n",
248 		       (void *) regs->psw.mask, (void *)regs->psw.addr);
249 
250 	buffer += sprintf(buffer, "User GPRS: " FOURLONG,
251 			  regs->gprs[0], regs->gprs[1],
252 			  regs->gprs[2], regs->gprs[3]);
253 	buffer += sprintf(buffer, "           " FOURLONG,
254 			  regs->gprs[4], regs->gprs[5],
255 			  regs->gprs[6], regs->gprs[7]);
256 	buffer += sprintf(buffer, "           " FOURLONG,
257 			  regs->gprs[8], regs->gprs[9],
258 			  regs->gprs[10], regs->gprs[11]);
259 	buffer += sprintf(buffer, "           " FOURLONG,
260 			  regs->gprs[12], regs->gprs[13],
261 			  regs->gprs[14], regs->gprs[15]);
262 	buffer += sprintf(buffer, "User ACRS: %08x %08x %08x %08x\n",
263 			  task->thread.acrs[0], task->thread.acrs[1],
264 			  task->thread.acrs[2], task->thread.acrs[3]);
265 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
266 			  task->thread.acrs[4], task->thread.acrs[5],
267 			  task->thread.acrs[6], task->thread.acrs[7]);
268 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
269 			  task->thread.acrs[8], task->thread.acrs[9],
270 			  task->thread.acrs[10], task->thread.acrs[11]);
271 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
272 			  task->thread.acrs[12], task->thread.acrs[13],
273 			  task->thread.acrs[14], task->thread.acrs[15]);
274 	return buffer;
275 }
276 
277 DEFINE_SPINLOCK(die_lock);
278 
279 void die(const char * str, struct pt_regs * regs, long err)
280 {
281 	static int die_counter;
282 
283 	debug_stop_all();
284 	console_verbose();
285 	spin_lock_irq(&die_lock);
286 	bust_spinlocks(1);
287 	printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
288         show_regs(regs);
289 	bust_spinlocks(0);
290         spin_unlock_irq(&die_lock);
291 	if (in_interrupt())
292 		panic("Fatal exception in interrupt");
293 	if (panic_on_oops)
294 		panic("Fatal exception: panic_on_oops");
295         do_exit(SIGSEGV);
296 }
297 
298 static void inline
299 report_user_fault(long interruption_code, struct pt_regs *regs)
300 {
301 #if defined(CONFIG_SYSCTL)
302 	if (!sysctl_userprocess_debug)
303 		return;
304 #endif
305 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
306 	printk("User process fault: interruption code 0x%lX\n",
307 	       interruption_code);
308 	show_regs(regs);
309 #endif
310 }
311 
312 static void inline do_trap(long interruption_code, int signr, char *str,
313                            struct pt_regs *regs, siginfo_t *info)
314 {
315 	/*
316 	 * We got all needed information from the lowcore and can
317 	 * now safely switch on interrupts.
318 	 */
319         if (regs->psw.mask & PSW_MASK_PSTATE)
320 		local_irq_enable();
321 
322         if (regs->psw.mask & PSW_MASK_PSTATE) {
323                 struct task_struct *tsk = current;
324 
325                 tsk->thread.trap_no = interruption_code & 0xffff;
326 		force_sig_info(signr, info, tsk);
327 		report_user_fault(interruption_code, regs);
328         } else {
329                 const struct exception_table_entry *fixup;
330                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
331                 if (fixup)
332                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
333                 else
334                         die(str, regs, interruption_code);
335         }
336 }
337 
338 static inline void *get_check_address(struct pt_regs *regs)
339 {
340 	return (void *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
341 }
342 
343 void do_single_step(struct pt_regs *regs)
344 {
345 	if ((current->ptrace & PT_PTRACED) != 0)
346 		force_sig(SIGTRAP, current);
347 }
348 
349 asmlinkage void
350 default_trap_handler(struct pt_regs * regs, long interruption_code)
351 {
352         if (regs->psw.mask & PSW_MASK_PSTATE) {
353 		local_irq_enable();
354 		do_exit(SIGSEGV);
355 		report_user_fault(interruption_code, regs);
356 	} else
357 		die("Unknown program exception", regs, interruption_code);
358 }
359 
360 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
361 asmlinkage void name(struct pt_regs * regs, long interruption_code) \
362 { \
363         siginfo_t info; \
364         info.si_signo = signr; \
365         info.si_errno = 0; \
366         info.si_code = sicode; \
367         info.si_addr = (void *)siaddr; \
368         do_trap(interruption_code, signr, str, regs, &info); \
369 }
370 
371 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
372 	      ILL_ILLADR, get_check_address(regs))
373 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
374 	      ILL_ILLOPN, get_check_address(regs))
375 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
376 	      FPE_INTDIV, get_check_address(regs))
377 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
378 	      FPE_INTOVF, get_check_address(regs))
379 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
380 	      FPE_FLTOVF, get_check_address(regs))
381 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
382 	      FPE_FLTUND, get_check_address(regs))
383 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
384 	      FPE_FLTRES, get_check_address(regs))
385 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
386 	      FPE_FLTDIV, get_check_address(regs))
387 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
388 	      FPE_FLTINV, get_check_address(regs))
389 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
390 	      ILL_ILLOPN, get_check_address(regs))
391 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
392 	      ILL_PRVOPC, get_check_address(regs))
393 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
394 	      ILL_ILLOPN, get_check_address(regs))
395 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
396 	      ILL_ILLOPN, get_check_address(regs))
397 
398 static inline void
399 do_fp_trap(struct pt_regs *regs, void *location,
400            int fpc, long interruption_code)
401 {
402 	siginfo_t si;
403 
404 	si.si_signo = SIGFPE;
405 	si.si_errno = 0;
406 	si.si_addr = location;
407 	si.si_code = 0;
408 	/* FPC[2] is Data Exception Code */
409 	if ((fpc & 0x00000300) == 0) {
410 		/* bits 6 and 7 of DXC are 0 iff IEEE exception */
411 		if (fpc & 0x8000) /* invalid fp operation */
412 			si.si_code = FPE_FLTINV;
413 		else if (fpc & 0x4000) /* div by 0 */
414 			si.si_code = FPE_FLTDIV;
415 		else if (fpc & 0x2000) /* overflow */
416 			si.si_code = FPE_FLTOVF;
417 		else if (fpc & 0x1000) /* underflow */
418 			si.si_code = FPE_FLTUND;
419 		else if (fpc & 0x0800) /* inexact */
420 			si.si_code = FPE_FLTRES;
421 	}
422 	current->thread.ieee_instruction_pointer = (addr_t) location;
423 	do_trap(interruption_code, SIGFPE,
424 		"floating point exception", regs, &si);
425 }
426 
427 asmlinkage void illegal_op(struct pt_regs * regs, long interruption_code)
428 {
429 	siginfo_t info;
430         __u8 opcode[6];
431 	__u16 *location;
432 	int signal = 0;
433 
434 	location = (__u16 *) get_check_address(regs);
435 
436 	/*
437 	 * We got all needed information from the lowcore and can
438 	 * now safely switch on interrupts.
439 	 */
440 	if (regs->psw.mask & PSW_MASK_PSTATE)
441 		local_irq_enable();
442 
443 	if (regs->psw.mask & PSW_MASK_PSTATE) {
444 		get_user(*((__u16 *) opcode), (__u16 __user *) location);
445 		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
446 			if (current->ptrace & PT_PTRACED)
447 				force_sig(SIGTRAP, current);
448 			else
449 				signal = SIGILL;
450 #ifdef CONFIG_MATHEMU
451 		} else if (opcode[0] == 0xb3) {
452 			get_user(*((__u16 *) (opcode+2)), location+1);
453 			signal = math_emu_b3(opcode, regs);
454                 } else if (opcode[0] == 0xed) {
455 			get_user(*((__u32 *) (opcode+2)),
456 				 (__u32 *)(location+1));
457 			signal = math_emu_ed(opcode, regs);
458 		} else if (*((__u16 *) opcode) == 0xb299) {
459 			get_user(*((__u16 *) (opcode+2)), location+1);
460 			signal = math_emu_srnm(opcode, regs);
461 		} else if (*((__u16 *) opcode) == 0xb29c) {
462 			get_user(*((__u16 *) (opcode+2)), location+1);
463 			signal = math_emu_stfpc(opcode, regs);
464 		} else if (*((__u16 *) opcode) == 0xb29d) {
465 			get_user(*((__u16 *) (opcode+2)), location+1);
466 			signal = math_emu_lfpc(opcode, regs);
467 #endif
468 		} else
469 			signal = SIGILL;
470 	} else
471 		signal = SIGILL;
472 
473 #ifdef CONFIG_MATHEMU
474         if (signal == SIGFPE)
475 		do_fp_trap(regs, location,
476                            current->thread.fp_regs.fpc, interruption_code);
477         else if (signal == SIGSEGV) {
478 		info.si_signo = signal;
479 		info.si_errno = 0;
480 		info.si_code = SEGV_MAPERR;
481 		info.si_addr = (void *) location;
482 		do_trap(interruption_code, signal,
483 			"user address fault", regs, &info);
484 	} else
485 #endif
486         if (signal) {
487 		info.si_signo = signal;
488 		info.si_errno = 0;
489 		info.si_code = ILL_ILLOPC;
490 		info.si_addr = (void *) location;
491 		do_trap(interruption_code, signal,
492 			"illegal operation", regs, &info);
493 	}
494 }
495 
496 
497 #ifdef CONFIG_MATHEMU
498 asmlinkage void
499 specification_exception(struct pt_regs * regs, long interruption_code)
500 {
501         __u8 opcode[6];
502 	__u16 *location = NULL;
503 	int signal = 0;
504 
505 	location = (__u16 *) get_check_address(regs);
506 
507 	/*
508 	 * We got all needed information from the lowcore and can
509 	 * now safely switch on interrupts.
510 	 */
511         if (regs->psw.mask & PSW_MASK_PSTATE)
512 		local_irq_enable();
513 
514         if (regs->psw.mask & PSW_MASK_PSTATE) {
515 		get_user(*((__u16 *) opcode), location);
516 		switch (opcode[0]) {
517 		case 0x28: /* LDR Rx,Ry   */
518 			signal = math_emu_ldr(opcode);
519 			break;
520 		case 0x38: /* LER Rx,Ry   */
521 			signal = math_emu_ler(opcode);
522 			break;
523 		case 0x60: /* STD R,D(X,B) */
524 			get_user(*((__u16 *) (opcode+2)), location+1);
525 			signal = math_emu_std(opcode, regs);
526 			break;
527 		case 0x68: /* LD R,D(X,B) */
528 			get_user(*((__u16 *) (opcode+2)), location+1);
529 			signal = math_emu_ld(opcode, regs);
530 			break;
531 		case 0x70: /* STE R,D(X,B) */
532 			get_user(*((__u16 *) (opcode+2)), location+1);
533 			signal = math_emu_ste(opcode, regs);
534 			break;
535 		case 0x78: /* LE R,D(X,B) */
536 			get_user(*((__u16 *) (opcode+2)), location+1);
537 			signal = math_emu_le(opcode, regs);
538 			break;
539 		default:
540 			signal = SIGILL;
541 			break;
542                 }
543         } else
544 		signal = SIGILL;
545 
546         if (signal == SIGFPE)
547 		do_fp_trap(regs, location,
548                            current->thread.fp_regs.fpc, interruption_code);
549         else if (signal) {
550 		siginfo_t info;
551 		info.si_signo = signal;
552 		info.si_errno = 0;
553 		info.si_code = ILL_ILLOPN;
554 		info.si_addr = location;
555 		do_trap(interruption_code, signal,
556 			"specification exception", regs, &info);
557 	}
558 }
559 #else
560 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
561 	      ILL_ILLOPN, get_check_address(regs));
562 #endif
563 
564 asmlinkage void data_exception(struct pt_regs * regs, long interruption_code)
565 {
566 	__u16 *location;
567 	int signal = 0;
568 
569 	location = (__u16 *) get_check_address(regs);
570 
571 	/*
572 	 * We got all needed information from the lowcore and can
573 	 * now safely switch on interrupts.
574 	 */
575 	if (regs->psw.mask & PSW_MASK_PSTATE)
576 		local_irq_enable();
577 
578 	if (MACHINE_HAS_IEEE)
579 		__asm__ volatile ("stfpc %0\n\t"
580 				  : "=m" (current->thread.fp_regs.fpc));
581 
582 #ifdef CONFIG_MATHEMU
583         else if (regs->psw.mask & PSW_MASK_PSTATE) {
584         	__u8 opcode[6];
585 		get_user(*((__u16 *) opcode), location);
586 		switch (opcode[0]) {
587 		case 0x28: /* LDR Rx,Ry   */
588 			signal = math_emu_ldr(opcode);
589 			break;
590 		case 0x38: /* LER Rx,Ry   */
591 			signal = math_emu_ler(opcode);
592 			break;
593 		case 0x60: /* STD R,D(X,B) */
594 			get_user(*((__u16 *) (opcode+2)), location+1);
595 			signal = math_emu_std(opcode, regs);
596 			break;
597 		case 0x68: /* LD R,D(X,B) */
598 			get_user(*((__u16 *) (opcode+2)), location+1);
599 			signal = math_emu_ld(opcode, regs);
600 			break;
601 		case 0x70: /* STE R,D(X,B) */
602 			get_user(*((__u16 *) (opcode+2)), location+1);
603 			signal = math_emu_ste(opcode, regs);
604 			break;
605 		case 0x78: /* LE R,D(X,B) */
606 			get_user(*((__u16 *) (opcode+2)), location+1);
607 			signal = math_emu_le(opcode, regs);
608 			break;
609 		case 0xb3:
610 			get_user(*((__u16 *) (opcode+2)), location+1);
611 			signal = math_emu_b3(opcode, regs);
612 			break;
613                 case 0xed:
614 			get_user(*((__u32 *) (opcode+2)),
615 				 (__u32 *)(location+1));
616 			signal = math_emu_ed(opcode, regs);
617 			break;
618 	        case 0xb2:
619 			if (opcode[1] == 0x99) {
620 				get_user(*((__u16 *) (opcode+2)), location+1);
621 				signal = math_emu_srnm(opcode, regs);
622 			} else if (opcode[1] == 0x9c) {
623 				get_user(*((__u16 *) (opcode+2)), location+1);
624 				signal = math_emu_stfpc(opcode, regs);
625 			} else if (opcode[1] == 0x9d) {
626 				get_user(*((__u16 *) (opcode+2)), location+1);
627 				signal = math_emu_lfpc(opcode, regs);
628 			} else
629 				signal = SIGILL;
630 			break;
631 		default:
632 			signal = SIGILL;
633 			break;
634                 }
635         }
636 #endif
637 	if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
638 		signal = SIGFPE;
639 	else
640 		signal = SIGILL;
641         if (signal == SIGFPE)
642 		do_fp_trap(regs, location,
643                            current->thread.fp_regs.fpc, interruption_code);
644         else if (signal) {
645 		siginfo_t info;
646 		info.si_signo = signal;
647 		info.si_errno = 0;
648 		info.si_code = ILL_ILLOPN;
649 		info.si_addr = location;
650 		do_trap(interruption_code, signal,
651 			"data exception", regs, &info);
652 	}
653 }
654 
655 asmlinkage void space_switch_exception(struct pt_regs * regs, long int_code)
656 {
657         siginfo_t info;
658 
659 	/* Set user psw back to home space mode. */
660 	if (regs->psw.mask & PSW_MASK_PSTATE)
661 		regs->psw.mask |= PSW_ASC_HOME;
662 	/* Send SIGILL. */
663         info.si_signo = SIGILL;
664         info.si_errno = 0;
665         info.si_code = ILL_PRVOPC;
666         info.si_addr = get_check_address(regs);
667         do_trap(int_code, SIGILL, "space switch event", regs, &info);
668 }
669 
670 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
671 {
672 	bust_spinlocks(1);
673 	printk("Kernel stack overflow.\n");
674 	show_regs(regs);
675 	bust_spinlocks(0);
676 	panic("Corrupt kernel stack, can't continue.");
677 }
678 
679 #ifndef CONFIG_ARCH_S390X
680 static int
681 pagex_reboot_event(struct notifier_block *this, unsigned long event, void *ptr)
682 {
683 	if (MACHINE_IS_VM)
684 		cpcmd("SET PAGEX OFF", NULL, 0, NULL);
685 	return NOTIFY_DONE;
686 }
687 
688 static struct notifier_block pagex_reboot_notifier = {
689 	.notifier_call = &pagex_reboot_event,
690 };
691 #endif
692 
693 /* init is done in lowcore.S and head.S */
694 
695 void __init trap_init(void)
696 {
697         int i;
698 
699         for (i = 0; i < 128; i++)
700           pgm_check_table[i] = &default_trap_handler;
701         pgm_check_table[1] = &illegal_op;
702         pgm_check_table[2] = &privileged_op;
703         pgm_check_table[3] = &execute_exception;
704         pgm_check_table[4] = &do_protection_exception;
705         pgm_check_table[5] = &addressing_exception;
706         pgm_check_table[6] = &specification_exception;
707         pgm_check_table[7] = &data_exception;
708         pgm_check_table[8] = &overflow_exception;
709         pgm_check_table[9] = &divide_exception;
710         pgm_check_table[0x0A] = &overflow_exception;
711         pgm_check_table[0x0B] = &divide_exception;
712         pgm_check_table[0x0C] = &hfp_overflow_exception;
713         pgm_check_table[0x0D] = &hfp_underflow_exception;
714         pgm_check_table[0x0E] = &hfp_significance_exception;
715         pgm_check_table[0x0F] = &hfp_divide_exception;
716         pgm_check_table[0x10] = &do_dat_exception;
717         pgm_check_table[0x11] = &do_dat_exception;
718         pgm_check_table[0x12] = &translation_exception;
719         pgm_check_table[0x13] = &special_op_exception;
720 #ifndef CONFIG_ARCH_S390X
721  	pgm_check_table[0x14] = &do_pseudo_page_fault;
722 #else /* CONFIG_ARCH_S390X */
723         pgm_check_table[0x38] = &do_dat_exception;
724 	pgm_check_table[0x39] = &do_dat_exception;
725 	pgm_check_table[0x3A] = &do_dat_exception;
726         pgm_check_table[0x3B] = &do_dat_exception;
727 #endif /* CONFIG_ARCH_S390X */
728         pgm_check_table[0x15] = &operand_exception;
729         pgm_check_table[0x1C] = &space_switch_exception;
730         pgm_check_table[0x1D] = &hfp_sqrt_exception;
731 	pgm_check_table[0x40] = &do_monitor_call;
732 
733 	if (MACHINE_IS_VM) {
734 		/*
735 		 * First try to get pfault pseudo page faults going.
736 		 * If this isn't available turn on pagex page faults.
737 		 */
738 #ifdef CONFIG_PFAULT
739 		/* request the 0x2603 external interrupt */
740 		if (register_early_external_interrupt(0x2603, pfault_interrupt,
741 						      &ext_int_pfault) != 0)
742 			panic("Couldn't request external interrupt 0x2603");
743 
744 		if (pfault_init() == 0)
745 			return;
746 
747 		/* Tough luck, no pfault. */
748 		unregister_early_external_interrupt(0x2603, pfault_interrupt,
749 						    &ext_int_pfault);
750 #endif
751 #ifndef CONFIG_ARCH_S390X
752 		register_reboot_notifier(&pagex_reboot_notifier);
753 		cpcmd("SET PAGEX ON", NULL, 0, NULL);
754 #endif
755 	}
756 }
757