xref: /linux/arch/s390/kernel/traps.c (revision e26207a3819684e9b4450a2d30bdd065fa92d9c7)
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/tracehook.h>
22 #include <linux/timer.h>
23 #include <linux/mm.h>
24 #include <linux/smp.h>
25 #include <linux/init.h>
26 #include <linux/interrupt.h>
27 #include <linux/seq_file.h>
28 #include <linux/delay.h>
29 #include <linux/module.h>
30 #include <linux/kdebug.h>
31 #include <linux/kallsyms.h>
32 #include <linux/reboot.h>
33 #include <linux/kprobes.h>
34 #include <linux/bug.h>
35 #include <linux/utsname.h>
36 #include <asm/system.h>
37 #include <asm/uaccess.h>
38 #include <asm/io.h>
39 #include <asm/atomic.h>
40 #include <asm/mathemu.h>
41 #include <asm/cpcmd.h>
42 #include <asm/s390_ext.h>
43 #include <asm/lowcore.h>
44 #include <asm/debug.h>
45 #include "entry.h"
46 
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 extern pgm_check_handler_t do_asce_exception;
60 
61 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
62 
63 #ifndef CONFIG_64BIT
64 #define LONG "%08lx "
65 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
66 static int kstack_depth_to_print = 12;
67 #else /* CONFIG_64BIT */
68 #define LONG "%016lx "
69 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
70 static int kstack_depth_to_print = 20;
71 #endif /* CONFIG_64BIT */
72 
73 /*
74  * For show_trace we have tree different stack to consider:
75  *   - the panic stack which is used if the kernel stack has overflown
76  *   - the asynchronous interrupt stack (cpu related)
77  *   - the synchronous kernel stack (process related)
78  * The stack trace can start at any of the three stack and can potentially
79  * touch all of them. The order is: panic stack, async stack, sync stack.
80  */
81 static unsigned long
82 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
83 {
84 	struct stack_frame *sf;
85 	struct pt_regs *regs;
86 
87 	while (1) {
88 		sp = sp & PSW_ADDR_INSN;
89 		if (sp < low || sp > high - sizeof(*sf))
90 			return sp;
91 		sf = (struct stack_frame *) sp;
92 		printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
93 		print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
94 		/* Follow the backchain. */
95 		while (1) {
96 			low = sp;
97 			sp = sf->back_chain & PSW_ADDR_INSN;
98 			if (!sp)
99 				break;
100 			if (sp <= low || sp > high - sizeof(*sf))
101 				return sp;
102 			sf = (struct stack_frame *) sp;
103 			printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
104 			print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
105 		}
106 		/* Zero backchain detected, check for interrupt frame. */
107 		sp = (unsigned long) (sf + 1);
108 		if (sp <= low || sp > high - sizeof(*regs))
109 			return sp;
110 		regs = (struct pt_regs *) sp;
111 		printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
112 		print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
113 		low = sp;
114 		sp = regs->gprs[15];
115 	}
116 }
117 
118 static void show_trace(struct task_struct *task, unsigned long *stack)
119 {
120 	register unsigned long __r15 asm ("15");
121 	unsigned long sp;
122 
123 	sp = (unsigned long) stack;
124 	if (!sp)
125 		sp = task ? task->thread.ksp : __r15;
126 	printk("Call Trace:\n");
127 #ifdef CONFIG_CHECK_STACK
128 	sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
129 			  S390_lowcore.panic_stack);
130 #endif
131 	sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
132 			  S390_lowcore.async_stack);
133 	if (task)
134 		__show_trace(sp, (unsigned long) task_stack_page(task),
135 			     (unsigned long) task_stack_page(task) + THREAD_SIZE);
136 	else
137 		__show_trace(sp, S390_lowcore.thread_info,
138 			     S390_lowcore.thread_info + THREAD_SIZE);
139 	if (!task)
140 		task = current;
141 	debug_show_held_locks(task);
142 }
143 
144 void show_stack(struct task_struct *task, unsigned long *sp)
145 {
146 	register unsigned long * __r15 asm ("15");
147 	unsigned long *stack;
148 	int i;
149 
150 	if (!sp)
151 		stack = task ? (unsigned long *) task->thread.ksp : __r15;
152 	else
153 		stack = sp;
154 
155 	for (i = 0; i < kstack_depth_to_print; i++) {
156 		if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
157 			break;
158 		if (i && ((i * sizeof (long) % 32) == 0))
159 			printk("\n       ");
160 		printk(LONG, *stack++);
161 	}
162 	printk("\n");
163 	show_trace(task, sp);
164 }
165 
166 static void show_last_breaking_event(struct pt_regs *regs)
167 {
168 #ifdef CONFIG_64BIT
169 	printk("Last Breaking-Event-Address:\n");
170 	printk(" [<%016lx>] ", regs->args[0] & PSW_ADDR_INSN);
171 	print_symbol("%s\n", regs->args[0] & PSW_ADDR_INSN);
172 #endif
173 }
174 
175 /*
176  * The architecture-independent dump_stack generator
177  */
178 void dump_stack(void)
179 {
180 	printk("CPU: %d %s %s %.*s\n",
181 	       task_thread_info(current)->cpu, print_tainted(),
182 	       init_utsname()->release,
183 	       (int)strcspn(init_utsname()->version, " "),
184 	       init_utsname()->version);
185 	printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
186 	       current->comm, current->pid, current,
187 	       (void *) current->thread.ksp);
188 	show_stack(NULL, NULL);
189 }
190 EXPORT_SYMBOL(dump_stack);
191 
192 static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
193 {
194 	return (regs->psw.mask & bits) / ((~bits + 1) & bits);
195 }
196 
197 void show_registers(struct pt_regs *regs)
198 {
199 	char *mode;
200 
201 	mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
202 	printk("%s PSW : %p %p",
203 	       mode, (void *) regs->psw.mask,
204 	       (void *) regs->psw.addr);
205 	print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
206 	printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
207 	       "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
208 	       mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
209 	       mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
210 	       mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
211 	       mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
212 	       mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
213 #ifdef CONFIG_64BIT
214 	printk(" EA:%x", mask_bits(regs, PSW_BASE_BITS));
215 #endif
216 	printk("\n%s GPRS: " FOURLONG, mode,
217 	       regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
218 	printk("           " FOURLONG,
219 	       regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
220 	printk("           " FOURLONG,
221 	       regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
222 	printk("           " FOURLONG,
223 	       regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
224 
225 	show_code(regs);
226 }
227 
228 void show_regs(struct pt_regs *regs)
229 {
230 	print_modules();
231 	printk("CPU: %d %s %s %.*s\n",
232 	       task_thread_info(current)->cpu, print_tainted(),
233 	       init_utsname()->release,
234 	       (int)strcspn(init_utsname()->version, " "),
235 	       init_utsname()->version);
236 	printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
237 	       current->comm, current->pid, current,
238 	       (void *) current->thread.ksp);
239 	show_registers(regs);
240 	/* Show stack backtrace if pt_regs is from kernel mode */
241 	if (!(regs->psw.mask & PSW_MASK_PSTATE))
242 		show_trace(NULL, (unsigned long *) regs->gprs[15]);
243 	show_last_breaking_event(regs);
244 }
245 
246 /* This is called from fs/proc/array.c */
247 void task_show_regs(struct seq_file *m, struct task_struct *task)
248 {
249 	struct pt_regs *regs;
250 
251 	regs = task_pt_regs(task);
252 	seq_printf(m, "task: %p, ksp: %p\n",
253 		       task, (void *)task->thread.ksp);
254 	seq_printf(m, "User PSW : %p %p\n",
255 		       (void *) regs->psw.mask, (void *)regs->psw.addr);
256 
257 	seq_printf(m, "User GPRS: " FOURLONG,
258 			  regs->gprs[0], regs->gprs[1],
259 			  regs->gprs[2], regs->gprs[3]);
260 	seq_printf(m, "           " FOURLONG,
261 			  regs->gprs[4], regs->gprs[5],
262 			  regs->gprs[6], regs->gprs[7]);
263 	seq_printf(m, "           " FOURLONG,
264 			  regs->gprs[8], regs->gprs[9],
265 			  regs->gprs[10], regs->gprs[11]);
266 	seq_printf(m, "           " FOURLONG,
267 			  regs->gprs[12], regs->gprs[13],
268 			  regs->gprs[14], regs->gprs[15]);
269 	seq_printf(m, "User ACRS: %08x %08x %08x %08x\n",
270 			  task->thread.acrs[0], task->thread.acrs[1],
271 			  task->thread.acrs[2], task->thread.acrs[3]);
272 	seq_printf(m, "           %08x %08x %08x %08x\n",
273 			  task->thread.acrs[4], task->thread.acrs[5],
274 			  task->thread.acrs[6], task->thread.acrs[7]);
275 	seq_printf(m, "           %08x %08x %08x %08x\n",
276 			  task->thread.acrs[8], task->thread.acrs[9],
277 			  task->thread.acrs[10], task->thread.acrs[11]);
278 	seq_printf(m, "           %08x %08x %08x %08x\n",
279 			  task->thread.acrs[12], task->thread.acrs[13],
280 			  task->thread.acrs[14], task->thread.acrs[15]);
281 }
282 
283 static DEFINE_SPINLOCK(die_lock);
284 
285 void die(const char * str, struct pt_regs * regs, long err)
286 {
287 	static int die_counter;
288 
289 	oops_enter();
290 	debug_stop_all();
291 	console_verbose();
292 	spin_lock_irq(&die_lock);
293 	bust_spinlocks(1);
294 	printk("%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
295 #ifdef CONFIG_PREEMPT
296 	printk("PREEMPT ");
297 #endif
298 #ifdef CONFIG_SMP
299 	printk("SMP ");
300 #endif
301 #ifdef CONFIG_DEBUG_PAGEALLOC
302 	printk("DEBUG_PAGEALLOC");
303 #endif
304 	printk("\n");
305 	notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
306 	show_regs(regs);
307 	bust_spinlocks(0);
308 	add_taint(TAINT_DIE);
309 	spin_unlock_irq(&die_lock);
310 	if (in_interrupt())
311 		panic("Fatal exception in interrupt");
312 	if (panic_on_oops)
313 		panic("Fatal exception: panic_on_oops");
314 	oops_exit();
315 	do_exit(SIGSEGV);
316 }
317 
318 static void inline
319 report_user_fault(long interruption_code, struct pt_regs *regs)
320 {
321 #if defined(CONFIG_SYSCTL)
322 	if (!sysctl_userprocess_debug)
323 		return;
324 #endif
325 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
326 	printk("User process fault: interruption code 0x%lX\n",
327 	       interruption_code);
328 	show_regs(regs);
329 #endif
330 }
331 
332 int is_valid_bugaddr(unsigned long addr)
333 {
334 	return 1;
335 }
336 
337 static void __kprobes inline do_trap(long interruption_code, int signr,
338 					char *str, struct pt_regs *regs,
339 					siginfo_t *info)
340 {
341 	/*
342 	 * We got all needed information from the lowcore and can
343 	 * now safely switch on interrupts.
344 	 */
345         if (regs->psw.mask & PSW_MASK_PSTATE)
346 		local_irq_enable();
347 
348 	if (notify_die(DIE_TRAP, str, regs, interruption_code,
349 				interruption_code, signr) == NOTIFY_STOP)
350 		return;
351 
352         if (regs->psw.mask & PSW_MASK_PSTATE) {
353                 struct task_struct *tsk = current;
354 
355                 tsk->thread.trap_no = interruption_code & 0xffff;
356 		force_sig_info(signr, info, tsk);
357 		report_user_fault(interruption_code, regs);
358         } else {
359                 const struct exception_table_entry *fixup;
360                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
361                 if (fixup)
362                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
363 		else {
364 			enum bug_trap_type btt;
365 
366 			btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
367 			if (btt == BUG_TRAP_TYPE_WARN)
368 				return;
369 			die(str, regs, interruption_code);
370 		}
371         }
372 }
373 
374 static inline void __user *get_check_address(struct pt_regs *regs)
375 {
376 	return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
377 }
378 
379 void __kprobes do_single_step(struct pt_regs *regs)
380 {
381 	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
382 					SIGTRAP) == NOTIFY_STOP){
383 		return;
384 	}
385 	if (tracehook_consider_fatal_signal(current, SIGTRAP))
386 		force_sig(SIGTRAP, current);
387 }
388 
389 static void default_trap_handler(struct pt_regs * regs, long interruption_code)
390 {
391         if (regs->psw.mask & PSW_MASK_PSTATE) {
392 		local_irq_enable();
393 		do_exit(SIGSEGV);
394 		report_user_fault(interruption_code, regs);
395 	} else
396 		die("Unknown program exception", regs, interruption_code);
397 }
398 
399 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
400 static void name(struct pt_regs * regs, long interruption_code) \
401 { \
402         siginfo_t info; \
403         info.si_signo = signr; \
404         info.si_errno = 0; \
405         info.si_code = sicode; \
406 	info.si_addr = siaddr; \
407         do_trap(interruption_code, signr, str, regs, &info); \
408 }
409 
410 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
411 	      ILL_ILLADR, get_check_address(regs))
412 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
413 	      ILL_ILLOPN, get_check_address(regs))
414 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
415 	      FPE_INTDIV, get_check_address(regs))
416 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
417 	      FPE_INTOVF, get_check_address(regs))
418 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
419 	      FPE_FLTOVF, get_check_address(regs))
420 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
421 	      FPE_FLTUND, get_check_address(regs))
422 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
423 	      FPE_FLTRES, get_check_address(regs))
424 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
425 	      FPE_FLTDIV, get_check_address(regs))
426 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
427 	      FPE_FLTINV, get_check_address(regs))
428 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
429 	      ILL_ILLOPN, get_check_address(regs))
430 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
431 	      ILL_PRVOPC, get_check_address(regs))
432 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
433 	      ILL_ILLOPN, get_check_address(regs))
434 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
435 	      ILL_ILLOPN, get_check_address(regs))
436 
437 static inline void
438 do_fp_trap(struct pt_regs *regs, void __user *location,
439            int fpc, long interruption_code)
440 {
441 	siginfo_t si;
442 
443 	si.si_signo = SIGFPE;
444 	si.si_errno = 0;
445 	si.si_addr = location;
446 	si.si_code = 0;
447 	/* FPC[2] is Data Exception Code */
448 	if ((fpc & 0x00000300) == 0) {
449 		/* bits 6 and 7 of DXC are 0 iff IEEE exception */
450 		if (fpc & 0x8000) /* invalid fp operation */
451 			si.si_code = FPE_FLTINV;
452 		else if (fpc & 0x4000) /* div by 0 */
453 			si.si_code = FPE_FLTDIV;
454 		else if (fpc & 0x2000) /* overflow */
455 			si.si_code = FPE_FLTOVF;
456 		else if (fpc & 0x1000) /* underflow */
457 			si.si_code = FPE_FLTUND;
458 		else if (fpc & 0x0800) /* inexact */
459 			si.si_code = FPE_FLTRES;
460 	}
461 	current->thread.ieee_instruction_pointer = (addr_t) location;
462 	do_trap(interruption_code, SIGFPE,
463 		"floating point exception", regs, &si);
464 }
465 
466 static void illegal_op(struct pt_regs * regs, long interruption_code)
467 {
468 	siginfo_t info;
469         __u8 opcode[6];
470 	__u16 __user *location;
471 	int signal = 0;
472 
473 	location = get_check_address(regs);
474 
475 	/*
476 	 * We got all needed information from the lowcore and can
477 	 * now safely switch on interrupts.
478 	 */
479 	if (regs->psw.mask & PSW_MASK_PSTATE)
480 		local_irq_enable();
481 
482 	if (regs->psw.mask & PSW_MASK_PSTATE) {
483 		if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
484 			return;
485 		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
486 			if (tracehook_consider_fatal_signal(current, SIGTRAP))
487 				force_sig(SIGTRAP, current);
488 			else
489 				signal = SIGILL;
490 #ifdef CONFIG_MATHEMU
491 		} else if (opcode[0] == 0xb3) {
492 			if (get_user(*((__u16 *) (opcode+2)), location+1))
493 				return;
494 			signal = math_emu_b3(opcode, regs);
495                 } else if (opcode[0] == 0xed) {
496 			if (get_user(*((__u32 *) (opcode+2)),
497 				     (__u32 __user *)(location+1)))
498 				return;
499 			signal = math_emu_ed(opcode, regs);
500 		} else if (*((__u16 *) opcode) == 0xb299) {
501 			if (get_user(*((__u16 *) (opcode+2)), location+1))
502 				return;
503 			signal = math_emu_srnm(opcode, regs);
504 		} else if (*((__u16 *) opcode) == 0xb29c) {
505 			if (get_user(*((__u16 *) (opcode+2)), location+1))
506 				return;
507 			signal = math_emu_stfpc(opcode, regs);
508 		} else if (*((__u16 *) opcode) == 0xb29d) {
509 			if (get_user(*((__u16 *) (opcode+2)), location+1))
510 				return;
511 			signal = math_emu_lfpc(opcode, regs);
512 #endif
513 		} else
514 			signal = SIGILL;
515 	} else {
516 		/*
517 		 * If we get an illegal op in kernel mode, send it through the
518 		 * kprobes notifier. If kprobes doesn't pick it up, SIGILL
519 		 */
520 		if (notify_die(DIE_BPT, "bpt", regs, interruption_code,
521 			       3, SIGTRAP) != NOTIFY_STOP)
522 			signal = SIGILL;
523 	}
524 
525 #ifdef CONFIG_MATHEMU
526         if (signal == SIGFPE)
527 		do_fp_trap(regs, location,
528                            current->thread.fp_regs.fpc, interruption_code);
529         else if (signal == SIGSEGV) {
530 		info.si_signo = signal;
531 		info.si_errno = 0;
532 		info.si_code = SEGV_MAPERR;
533 		info.si_addr = (void __user *) location;
534 		do_trap(interruption_code, signal,
535 			"user address fault", regs, &info);
536 	} else
537 #endif
538         if (signal) {
539 		info.si_signo = signal;
540 		info.si_errno = 0;
541 		info.si_code = ILL_ILLOPC;
542 		info.si_addr = (void __user *) location;
543 		do_trap(interruption_code, signal,
544 			"illegal operation", regs, &info);
545 	}
546 }
547 
548 
549 #ifdef CONFIG_MATHEMU
550 asmlinkage void
551 specification_exception(struct pt_regs * regs, long interruption_code)
552 {
553         __u8 opcode[6];
554 	__u16 __user *location = NULL;
555 	int signal = 0;
556 
557 	location = (__u16 __user *) get_check_address(regs);
558 
559 	/*
560 	 * We got all needed information from the lowcore and can
561 	 * now safely switch on interrupts.
562 	 */
563         if (regs->psw.mask & PSW_MASK_PSTATE)
564 		local_irq_enable();
565 
566         if (regs->psw.mask & PSW_MASK_PSTATE) {
567 		get_user(*((__u16 *) opcode), location);
568 		switch (opcode[0]) {
569 		case 0x28: /* LDR Rx,Ry   */
570 			signal = math_emu_ldr(opcode);
571 			break;
572 		case 0x38: /* LER Rx,Ry   */
573 			signal = math_emu_ler(opcode);
574 			break;
575 		case 0x60: /* STD R,D(X,B) */
576 			get_user(*((__u16 *) (opcode+2)), location+1);
577 			signal = math_emu_std(opcode, regs);
578 			break;
579 		case 0x68: /* LD R,D(X,B) */
580 			get_user(*((__u16 *) (opcode+2)), location+1);
581 			signal = math_emu_ld(opcode, regs);
582 			break;
583 		case 0x70: /* STE R,D(X,B) */
584 			get_user(*((__u16 *) (opcode+2)), location+1);
585 			signal = math_emu_ste(opcode, regs);
586 			break;
587 		case 0x78: /* LE R,D(X,B) */
588 			get_user(*((__u16 *) (opcode+2)), location+1);
589 			signal = math_emu_le(opcode, regs);
590 			break;
591 		default:
592 			signal = SIGILL;
593 			break;
594                 }
595         } else
596 		signal = SIGILL;
597 
598         if (signal == SIGFPE)
599 		do_fp_trap(regs, location,
600                            current->thread.fp_regs.fpc, interruption_code);
601         else if (signal) {
602 		siginfo_t info;
603 		info.si_signo = signal;
604 		info.si_errno = 0;
605 		info.si_code = ILL_ILLOPN;
606 		info.si_addr = location;
607 		do_trap(interruption_code, signal,
608 			"specification exception", regs, &info);
609 	}
610 }
611 #else
612 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
613 	      ILL_ILLOPN, get_check_address(regs));
614 #endif
615 
616 static void data_exception(struct pt_regs * regs, long interruption_code)
617 {
618 	__u16 __user *location;
619 	int signal = 0;
620 
621 	location = get_check_address(regs);
622 
623 	/*
624 	 * We got all needed information from the lowcore and can
625 	 * now safely switch on interrupts.
626 	 */
627 	if (regs->psw.mask & PSW_MASK_PSTATE)
628 		local_irq_enable();
629 
630 	if (MACHINE_HAS_IEEE)
631 		asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
632 
633 #ifdef CONFIG_MATHEMU
634         else if (regs->psw.mask & PSW_MASK_PSTATE) {
635         	__u8 opcode[6];
636 		get_user(*((__u16 *) opcode), location);
637 		switch (opcode[0]) {
638 		case 0x28: /* LDR Rx,Ry   */
639 			signal = math_emu_ldr(opcode);
640 			break;
641 		case 0x38: /* LER Rx,Ry   */
642 			signal = math_emu_ler(opcode);
643 			break;
644 		case 0x60: /* STD R,D(X,B) */
645 			get_user(*((__u16 *) (opcode+2)), location+1);
646 			signal = math_emu_std(opcode, regs);
647 			break;
648 		case 0x68: /* LD R,D(X,B) */
649 			get_user(*((__u16 *) (opcode+2)), location+1);
650 			signal = math_emu_ld(opcode, regs);
651 			break;
652 		case 0x70: /* STE R,D(X,B) */
653 			get_user(*((__u16 *) (opcode+2)), location+1);
654 			signal = math_emu_ste(opcode, regs);
655 			break;
656 		case 0x78: /* LE R,D(X,B) */
657 			get_user(*((__u16 *) (opcode+2)), location+1);
658 			signal = math_emu_le(opcode, regs);
659 			break;
660 		case 0xb3:
661 			get_user(*((__u16 *) (opcode+2)), location+1);
662 			signal = math_emu_b3(opcode, regs);
663 			break;
664                 case 0xed:
665 			get_user(*((__u32 *) (opcode+2)),
666 				 (__u32 __user *)(location+1));
667 			signal = math_emu_ed(opcode, regs);
668 			break;
669 	        case 0xb2:
670 			if (opcode[1] == 0x99) {
671 				get_user(*((__u16 *) (opcode+2)), location+1);
672 				signal = math_emu_srnm(opcode, regs);
673 			} else if (opcode[1] == 0x9c) {
674 				get_user(*((__u16 *) (opcode+2)), location+1);
675 				signal = math_emu_stfpc(opcode, regs);
676 			} else if (opcode[1] == 0x9d) {
677 				get_user(*((__u16 *) (opcode+2)), location+1);
678 				signal = math_emu_lfpc(opcode, regs);
679 			} else
680 				signal = SIGILL;
681 			break;
682 		default:
683 			signal = SIGILL;
684 			break;
685                 }
686         }
687 #endif
688 	if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
689 		signal = SIGFPE;
690 	else
691 		signal = SIGILL;
692         if (signal == SIGFPE)
693 		do_fp_trap(regs, location,
694                            current->thread.fp_regs.fpc, interruption_code);
695         else if (signal) {
696 		siginfo_t info;
697 		info.si_signo = signal;
698 		info.si_errno = 0;
699 		info.si_code = ILL_ILLOPN;
700 		info.si_addr = location;
701 		do_trap(interruption_code, signal,
702 			"data exception", regs, &info);
703 	}
704 }
705 
706 static void space_switch_exception(struct pt_regs * regs, long int_code)
707 {
708         siginfo_t info;
709 
710 	/* Set user psw back to home space mode. */
711 	if (regs->psw.mask & PSW_MASK_PSTATE)
712 		regs->psw.mask |= PSW_ASC_HOME;
713 	/* Send SIGILL. */
714         info.si_signo = SIGILL;
715         info.si_errno = 0;
716         info.si_code = ILL_PRVOPC;
717         info.si_addr = get_check_address(regs);
718         do_trap(int_code, SIGILL, "space switch event", regs, &info);
719 }
720 
721 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
722 {
723 	bust_spinlocks(1);
724 	printk("Kernel stack overflow.\n");
725 	show_regs(regs);
726 	bust_spinlocks(0);
727 	panic("Corrupt kernel stack, can't continue.");
728 }
729 
730 /* init is done in lowcore.S and head.S */
731 
732 void __init trap_init(void)
733 {
734         int i;
735 
736         for (i = 0; i < 128; i++)
737           pgm_check_table[i] = &default_trap_handler;
738         pgm_check_table[1] = &illegal_op;
739         pgm_check_table[2] = &privileged_op;
740         pgm_check_table[3] = &execute_exception;
741         pgm_check_table[4] = &do_protection_exception;
742         pgm_check_table[5] = &addressing_exception;
743         pgm_check_table[6] = &specification_exception;
744         pgm_check_table[7] = &data_exception;
745         pgm_check_table[8] = &overflow_exception;
746         pgm_check_table[9] = &divide_exception;
747         pgm_check_table[0x0A] = &overflow_exception;
748         pgm_check_table[0x0B] = &divide_exception;
749         pgm_check_table[0x0C] = &hfp_overflow_exception;
750         pgm_check_table[0x0D] = &hfp_underflow_exception;
751         pgm_check_table[0x0E] = &hfp_significance_exception;
752         pgm_check_table[0x0F] = &hfp_divide_exception;
753         pgm_check_table[0x10] = &do_dat_exception;
754         pgm_check_table[0x11] = &do_dat_exception;
755         pgm_check_table[0x12] = &translation_exception;
756         pgm_check_table[0x13] = &special_op_exception;
757 #ifdef CONFIG_64BIT
758 	pgm_check_table[0x38] = &do_asce_exception;
759 	pgm_check_table[0x39] = &do_dat_exception;
760 	pgm_check_table[0x3A] = &do_dat_exception;
761         pgm_check_table[0x3B] = &do_dat_exception;
762 #endif /* CONFIG_64BIT */
763         pgm_check_table[0x15] = &operand_exception;
764         pgm_check_table[0x1C] = &space_switch_exception;
765         pgm_check_table[0x1D] = &hfp_sqrt_exception;
766 	pfault_irq_init();
767 }
768