xref: /openbmc/linux/arch/s390/kernel/traps.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
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/init.h>
26 #include <linux/interrupt.h>
27 #include <linux/delay.h>
28 #include <linux/module.h>
29 #include <linux/kdebug.h>
30 #include <linux/kallsyms.h>
31 #include <linux/reboot.h>
32 #include <linux/kprobes.h>
33 #include <linux/bug.h>
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_monitor_call;
61 
62 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
63 
64 #ifndef CONFIG_64BIT
65 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
66 static int kstack_depth_to_print = 12;
67 #else /* CONFIG_64BIT */
68 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
69 static int kstack_depth_to_print = 20;
70 #endif /* CONFIG_64BIT */
71 
72 /*
73  * For show_trace we have tree different stack to consider:
74  *   - the panic stack which is used if the kernel stack has overflown
75  *   - the asynchronous interrupt stack (cpu related)
76  *   - the synchronous kernel stack (process related)
77  * The stack trace can start at any of the three stack and can potentially
78  * touch all of them. The order is: panic stack, async stack, sync stack.
79  */
80 static unsigned long
81 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
82 {
83 	struct stack_frame *sf;
84 	struct pt_regs *regs;
85 
86 	while (1) {
87 		sp = sp & PSW_ADDR_INSN;
88 		if (sp < low || sp > high - sizeof(*sf))
89 			return sp;
90 		sf = (struct stack_frame *) sp;
91 		printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
92 		print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
93 		/* Follow the backchain. */
94 		while (1) {
95 			low = sp;
96 			sp = sf->back_chain & PSW_ADDR_INSN;
97 			if (!sp)
98 				break;
99 			if (sp <= low || sp > high - sizeof(*sf))
100 				return sp;
101 			sf = (struct stack_frame *) sp;
102 			printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
103 			print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
104 		}
105 		/* Zero backchain detected, check for interrupt frame. */
106 		sp = (unsigned long) (sf + 1);
107 		if (sp <= low || sp > high - sizeof(*regs))
108 			return sp;
109 		regs = (struct pt_regs *) sp;
110 		printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
111 		print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
112 		low = sp;
113 		sp = regs->gprs[15];
114 	}
115 }
116 
117 void show_trace(struct task_struct *task, unsigned long *stack)
118 {
119 	register unsigned long __r15 asm ("15");
120 	unsigned long sp;
121 
122 	sp = (unsigned long) stack;
123 	if (!sp)
124 		sp = task ? task->thread.ksp : __r15;
125 	printk("Call Trace:\n");
126 #ifdef CONFIG_CHECK_STACK
127 	sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
128 			  S390_lowcore.panic_stack);
129 #endif
130 	sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
131 			  S390_lowcore.async_stack);
132 	if (task)
133 		__show_trace(sp, (unsigned long) task_stack_page(task),
134 			     (unsigned long) task_stack_page(task) + THREAD_SIZE);
135 	else
136 		__show_trace(sp, S390_lowcore.thread_info,
137 			     S390_lowcore.thread_info + THREAD_SIZE);
138 	printk("\n");
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("%p ", (void *)*stack++);
161 	}
162 	printk("\n");
163 	show_trace(task, sp);
164 }
165 
166 /*
167  * The architecture-independent dump_stack generator
168  */
169 void dump_stack(void)
170 {
171 	show_stack(NULL, NULL);
172 }
173 
174 EXPORT_SYMBOL(dump_stack);
175 
176 static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
177 {
178 	return (regs->psw.mask & bits) / ((~bits + 1) & bits);
179 }
180 
181 void show_registers(struct pt_regs *regs)
182 {
183 	char *mode;
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("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
191 	       "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
192 	       mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
193 	       mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
194 	       mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
195 	       mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
196 	       mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
197 #ifdef CONFIG_64BIT
198 	printk(" EA:%x", mask_bits(regs, PSW_BASE_BITS));
199 #endif
200 	printk("\n%s GPRS: " FOURLONG, mode,
201 	       regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
202 	printk("           " FOURLONG,
203 	       regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
204 	printk("           " FOURLONG,
205 	       regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
206 	printk("           " FOURLONG,
207 	       regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
208 
209 	show_code(regs);
210 }
211 
212 /* This is called from fs/proc/array.c */
213 char *task_show_regs(struct task_struct *task, char *buffer)
214 {
215 	struct pt_regs *regs;
216 
217 	regs = task_pt_regs(task);
218 	buffer += sprintf(buffer, "task: %p, ksp: %p\n",
219 		       task, (void *)task->thread.ksp);
220 	buffer += sprintf(buffer, "User PSW : %p %p\n",
221 		       (void *) regs->psw.mask, (void *)regs->psw.addr);
222 
223 	buffer += sprintf(buffer, "User GPRS: " FOURLONG,
224 			  regs->gprs[0], regs->gprs[1],
225 			  regs->gprs[2], regs->gprs[3]);
226 	buffer += sprintf(buffer, "           " FOURLONG,
227 			  regs->gprs[4], regs->gprs[5],
228 			  regs->gprs[6], regs->gprs[7]);
229 	buffer += sprintf(buffer, "           " FOURLONG,
230 			  regs->gprs[8], regs->gprs[9],
231 			  regs->gprs[10], regs->gprs[11]);
232 	buffer += sprintf(buffer, "           " FOURLONG,
233 			  regs->gprs[12], regs->gprs[13],
234 			  regs->gprs[14], regs->gprs[15]);
235 	buffer += sprintf(buffer, "User ACRS: %08x %08x %08x %08x\n",
236 			  task->thread.acrs[0], task->thread.acrs[1],
237 			  task->thread.acrs[2], task->thread.acrs[3]);
238 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
239 			  task->thread.acrs[4], task->thread.acrs[5],
240 			  task->thread.acrs[6], task->thread.acrs[7]);
241 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
242 			  task->thread.acrs[8], task->thread.acrs[9],
243 			  task->thread.acrs[10], task->thread.acrs[11]);
244 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
245 			  task->thread.acrs[12], task->thread.acrs[13],
246 			  task->thread.acrs[14], task->thread.acrs[15]);
247 	return buffer;
248 }
249 
250 static DEFINE_SPINLOCK(die_lock);
251 
252 void die(const char * str, struct pt_regs * regs, long err)
253 {
254 	static int die_counter;
255 
256 	oops_enter();
257 	debug_stop_all();
258 	console_verbose();
259 	spin_lock_irq(&die_lock);
260 	bust_spinlocks(1);
261 	printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
262 	print_modules();
263 	show_regs(regs);
264 	bust_spinlocks(0);
265 	add_taint(TAINT_DIE);
266 	spin_unlock_irq(&die_lock);
267 	if (in_interrupt())
268 		panic("Fatal exception in interrupt");
269 	if (panic_on_oops)
270 		panic("Fatal exception: panic_on_oops");
271 	oops_exit();
272 	do_exit(SIGSEGV);
273 }
274 
275 static void inline
276 report_user_fault(long interruption_code, struct pt_regs *regs)
277 {
278 #if defined(CONFIG_SYSCTL)
279 	if (!sysctl_userprocess_debug)
280 		return;
281 #endif
282 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
283 	printk("User process fault: interruption code 0x%lX\n",
284 	       interruption_code);
285 	show_regs(regs);
286 #endif
287 }
288 
289 int is_valid_bugaddr(unsigned long addr)
290 {
291 	return 1;
292 }
293 
294 static void __kprobes inline do_trap(long interruption_code, int signr,
295 					char *str, struct pt_regs *regs,
296 					siginfo_t *info)
297 {
298 	/*
299 	 * We got all needed information from the lowcore and can
300 	 * now safely switch on interrupts.
301 	 */
302         if (regs->psw.mask & PSW_MASK_PSTATE)
303 		local_irq_enable();
304 
305 	if (notify_die(DIE_TRAP, str, regs, interruption_code,
306 				interruption_code, signr) == NOTIFY_STOP)
307 		return;
308 
309         if (regs->psw.mask & PSW_MASK_PSTATE) {
310                 struct task_struct *tsk = current;
311 
312                 tsk->thread.trap_no = interruption_code & 0xffff;
313 		force_sig_info(signr, info, tsk);
314 		report_user_fault(interruption_code, regs);
315         } else {
316                 const struct exception_table_entry *fixup;
317                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
318                 if (fixup)
319                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
320 		else {
321 			enum bug_trap_type btt;
322 
323 			btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
324 			if (btt == BUG_TRAP_TYPE_WARN)
325 				return;
326 			die(str, regs, interruption_code);
327 		}
328         }
329 }
330 
331 static inline void __user *get_check_address(struct pt_regs *regs)
332 {
333 	return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
334 }
335 
336 void __kprobes do_single_step(struct pt_regs *regs)
337 {
338 	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
339 					SIGTRAP) == NOTIFY_STOP){
340 		return;
341 	}
342 	if ((current->ptrace & PT_PTRACED) != 0)
343 		force_sig(SIGTRAP, current);
344 }
345 
346 static void 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 static 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 = 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 __user *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 static void illegal_op(struct pt_regs * regs, long interruption_code)
424 {
425 	siginfo_t info;
426         __u8 opcode[6];
427 	__u16 __user *location;
428 	int signal = 0;
429 
430 	location = 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 		if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
441 			return;
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 			if (get_user(*((__u16 *) (opcode+2)), location+1))
450 				return;
451 			signal = math_emu_b3(opcode, regs);
452                 } else if (opcode[0] == 0xed) {
453 			if (get_user(*((__u32 *) (opcode+2)),
454 				     (__u32 __user *)(location+1)))
455 				return;
456 			signal = math_emu_ed(opcode, regs);
457 		} else if (*((__u16 *) opcode) == 0xb299) {
458 			if (get_user(*((__u16 *) (opcode+2)), location+1))
459 				return;
460 			signal = math_emu_srnm(opcode, regs);
461 		} else if (*((__u16 *) opcode) == 0xb29c) {
462 			if (get_user(*((__u16 *) (opcode+2)), location+1))
463 				return;
464 			signal = math_emu_stfpc(opcode, regs);
465 		} else if (*((__u16 *) opcode) == 0xb29d) {
466 			if (get_user(*((__u16 *) (opcode+2)), location+1))
467 				return;
468 			signal = math_emu_lfpc(opcode, regs);
469 #endif
470 		} else
471 			signal = SIGILL;
472 	} else {
473 		/*
474 		 * If we get an illegal op in kernel mode, send it through the
475 		 * kprobes notifier. If kprobes doesn't pick it up, SIGILL
476 		 */
477 		if (notify_die(DIE_BPT, "bpt", regs, interruption_code,
478 			       3, SIGTRAP) != NOTIFY_STOP)
479 			signal = SIGILL;
480 	}
481 
482 #ifdef CONFIG_MATHEMU
483         if (signal == SIGFPE)
484 		do_fp_trap(regs, location,
485                            current->thread.fp_regs.fpc, interruption_code);
486         else if (signal == SIGSEGV) {
487 		info.si_signo = signal;
488 		info.si_errno = 0;
489 		info.si_code = SEGV_MAPERR;
490 		info.si_addr = (void __user *) location;
491 		do_trap(interruption_code, signal,
492 			"user address fault", regs, &info);
493 	} else
494 #endif
495         if (signal) {
496 		info.si_signo = signal;
497 		info.si_errno = 0;
498 		info.si_code = ILL_ILLOPC;
499 		info.si_addr = (void __user *) location;
500 		do_trap(interruption_code, signal,
501 			"illegal operation", regs, &info);
502 	}
503 }
504 
505 
506 #ifdef CONFIG_MATHEMU
507 asmlinkage void
508 specification_exception(struct pt_regs * regs, long interruption_code)
509 {
510         __u8 opcode[6];
511 	__u16 __user *location = NULL;
512 	int signal = 0;
513 
514 	location = (__u16 __user *) get_check_address(regs);
515 
516 	/*
517 	 * We got all needed information from the lowcore and can
518 	 * now safely switch on interrupts.
519 	 */
520         if (regs->psw.mask & PSW_MASK_PSTATE)
521 		local_irq_enable();
522 
523         if (regs->psw.mask & PSW_MASK_PSTATE) {
524 		get_user(*((__u16 *) opcode), location);
525 		switch (opcode[0]) {
526 		case 0x28: /* LDR Rx,Ry   */
527 			signal = math_emu_ldr(opcode);
528 			break;
529 		case 0x38: /* LER Rx,Ry   */
530 			signal = math_emu_ler(opcode);
531 			break;
532 		case 0x60: /* STD R,D(X,B) */
533 			get_user(*((__u16 *) (opcode+2)), location+1);
534 			signal = math_emu_std(opcode, regs);
535 			break;
536 		case 0x68: /* LD R,D(X,B) */
537 			get_user(*((__u16 *) (opcode+2)), location+1);
538 			signal = math_emu_ld(opcode, regs);
539 			break;
540 		case 0x70: /* STE R,D(X,B) */
541 			get_user(*((__u16 *) (opcode+2)), location+1);
542 			signal = math_emu_ste(opcode, regs);
543 			break;
544 		case 0x78: /* LE R,D(X,B) */
545 			get_user(*((__u16 *) (opcode+2)), location+1);
546 			signal = math_emu_le(opcode, regs);
547 			break;
548 		default:
549 			signal = SIGILL;
550 			break;
551                 }
552         } else
553 		signal = SIGILL;
554 
555         if (signal == SIGFPE)
556 		do_fp_trap(regs, location,
557                            current->thread.fp_regs.fpc, interruption_code);
558         else if (signal) {
559 		siginfo_t info;
560 		info.si_signo = signal;
561 		info.si_errno = 0;
562 		info.si_code = ILL_ILLOPN;
563 		info.si_addr = location;
564 		do_trap(interruption_code, signal,
565 			"specification exception", regs, &info);
566 	}
567 }
568 #else
569 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
570 	      ILL_ILLOPN, get_check_address(regs));
571 #endif
572 
573 static void data_exception(struct pt_regs * regs, long interruption_code)
574 {
575 	__u16 __user *location;
576 	int signal = 0;
577 
578 	location = get_check_address(regs);
579 
580 	/*
581 	 * We got all needed information from the lowcore and can
582 	 * now safely switch on interrupts.
583 	 */
584 	if (regs->psw.mask & PSW_MASK_PSTATE)
585 		local_irq_enable();
586 
587 	if (MACHINE_HAS_IEEE)
588 		asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
589 
590 #ifdef CONFIG_MATHEMU
591         else if (regs->psw.mask & PSW_MASK_PSTATE) {
592         	__u8 opcode[6];
593 		get_user(*((__u16 *) opcode), location);
594 		switch (opcode[0]) {
595 		case 0x28: /* LDR Rx,Ry   */
596 			signal = math_emu_ldr(opcode);
597 			break;
598 		case 0x38: /* LER Rx,Ry   */
599 			signal = math_emu_ler(opcode);
600 			break;
601 		case 0x60: /* STD R,D(X,B) */
602 			get_user(*((__u16 *) (opcode+2)), location+1);
603 			signal = math_emu_std(opcode, regs);
604 			break;
605 		case 0x68: /* LD R,D(X,B) */
606 			get_user(*((__u16 *) (opcode+2)), location+1);
607 			signal = math_emu_ld(opcode, regs);
608 			break;
609 		case 0x70: /* STE R,D(X,B) */
610 			get_user(*((__u16 *) (opcode+2)), location+1);
611 			signal = math_emu_ste(opcode, regs);
612 			break;
613 		case 0x78: /* LE R,D(X,B) */
614 			get_user(*((__u16 *) (opcode+2)), location+1);
615 			signal = math_emu_le(opcode, regs);
616 			break;
617 		case 0xb3:
618 			get_user(*((__u16 *) (opcode+2)), location+1);
619 			signal = math_emu_b3(opcode, regs);
620 			break;
621                 case 0xed:
622 			get_user(*((__u32 *) (opcode+2)),
623 				 (__u32 __user *)(location+1));
624 			signal = math_emu_ed(opcode, regs);
625 			break;
626 	        case 0xb2:
627 			if (opcode[1] == 0x99) {
628 				get_user(*((__u16 *) (opcode+2)), location+1);
629 				signal = math_emu_srnm(opcode, regs);
630 			} else if (opcode[1] == 0x9c) {
631 				get_user(*((__u16 *) (opcode+2)), location+1);
632 				signal = math_emu_stfpc(opcode, regs);
633 			} else if (opcode[1] == 0x9d) {
634 				get_user(*((__u16 *) (opcode+2)), location+1);
635 				signal = math_emu_lfpc(opcode, regs);
636 			} else
637 				signal = SIGILL;
638 			break;
639 		default:
640 			signal = SIGILL;
641 			break;
642                 }
643         }
644 #endif
645 	if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
646 		signal = SIGFPE;
647 	else
648 		signal = SIGILL;
649         if (signal == SIGFPE)
650 		do_fp_trap(regs, location,
651                            current->thread.fp_regs.fpc, interruption_code);
652         else if (signal) {
653 		siginfo_t info;
654 		info.si_signo = signal;
655 		info.si_errno = 0;
656 		info.si_code = ILL_ILLOPN;
657 		info.si_addr = location;
658 		do_trap(interruption_code, signal,
659 			"data exception", regs, &info);
660 	}
661 }
662 
663 static void space_switch_exception(struct pt_regs * regs, long int_code)
664 {
665         siginfo_t info;
666 
667 	/* Set user psw back to home space mode. */
668 	if (regs->psw.mask & PSW_MASK_PSTATE)
669 		regs->psw.mask |= PSW_ASC_HOME;
670 	/* Send SIGILL. */
671         info.si_signo = SIGILL;
672         info.si_errno = 0;
673         info.si_code = ILL_PRVOPC;
674         info.si_addr = get_check_address(regs);
675         do_trap(int_code, SIGILL, "space switch event", regs, &info);
676 }
677 
678 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
679 {
680 	bust_spinlocks(1);
681 	printk("Kernel stack overflow.\n");
682 	show_regs(regs);
683 	bust_spinlocks(0);
684 	panic("Corrupt kernel stack, can't continue.");
685 }
686 
687 /* init is done in lowcore.S and head.S */
688 
689 void __init trap_init(void)
690 {
691         int i;
692 
693         for (i = 0; i < 128; i++)
694           pgm_check_table[i] = &default_trap_handler;
695         pgm_check_table[1] = &illegal_op;
696         pgm_check_table[2] = &privileged_op;
697         pgm_check_table[3] = &execute_exception;
698         pgm_check_table[4] = &do_protection_exception;
699         pgm_check_table[5] = &addressing_exception;
700         pgm_check_table[6] = &specification_exception;
701         pgm_check_table[7] = &data_exception;
702         pgm_check_table[8] = &overflow_exception;
703         pgm_check_table[9] = &divide_exception;
704         pgm_check_table[0x0A] = &overflow_exception;
705         pgm_check_table[0x0B] = &divide_exception;
706         pgm_check_table[0x0C] = &hfp_overflow_exception;
707         pgm_check_table[0x0D] = &hfp_underflow_exception;
708         pgm_check_table[0x0E] = &hfp_significance_exception;
709         pgm_check_table[0x0F] = &hfp_divide_exception;
710         pgm_check_table[0x10] = &do_dat_exception;
711         pgm_check_table[0x11] = &do_dat_exception;
712         pgm_check_table[0x12] = &translation_exception;
713         pgm_check_table[0x13] = &special_op_exception;
714 #ifdef CONFIG_64BIT
715         pgm_check_table[0x38] = &do_dat_exception;
716 	pgm_check_table[0x39] = &do_dat_exception;
717 	pgm_check_table[0x3A] = &do_dat_exception;
718         pgm_check_table[0x3B] = &do_dat_exception;
719 #endif /* CONFIG_64BIT */
720         pgm_check_table[0x15] = &operand_exception;
721         pgm_check_table[0x1C] = &space_switch_exception;
722         pgm_check_table[0x1D] = &hfp_sqrt_exception;
723 	pgm_check_table[0x40] = &do_monitor_call;
724 	pfault_irq_init();
725 }
726