xref: /linux/arch/s390/kernel/traps.c (revision 606d099cdd1080bbb50ea50dc52d98252f8f10a1)
1 /*
2  *  arch/s390/kernel/traps.c
3  *
4  *  S390 version
5  *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
6  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
7  *               Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
8  *
9  *  Derived from "arch/i386/kernel/traps.c"
10  *    Copyright (C) 1991, 1992 Linus Torvalds
11  */
12 
13 /*
14  * 'Traps.c' handles hardware traps and faults after we have saved some
15  * state in 'asm.s'.
16  */
17 #include <linux/sched.h>
18 #include <linux/kernel.h>
19 #include <linux/string.h>
20 #include <linux/errno.h>
21 #include <linux/ptrace.h>
22 #include <linux/timer.h>
23 #include <linux/mm.h>
24 #include <linux/smp.h>
25 #include <linux/smp_lock.h>
26 #include <linux/init.h>
27 #include <linux/interrupt.h>
28 #include <linux/delay.h>
29 #include <linux/module.h>
30 #include <linux/kallsyms.h>
31 #include <linux/reboot.h>
32 #include <linux/kprobes.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 #include <asm/kdebug.h>
44 
45 /* Called from entry.S only */
46 extern void handle_per_exception(struct pt_regs *regs);
47 
48 typedef void pgm_check_handler_t(struct pt_regs *, long);
49 pgm_check_handler_t *pgm_check_table[128];
50 
51 #ifdef CONFIG_SYSCTL
52 #ifdef CONFIG_PROCESS_DEBUG
53 int sysctl_userprocess_debug = 1;
54 #else
55 int sysctl_userprocess_debug = 0;
56 #endif
57 #endif
58 
59 extern pgm_check_handler_t do_protection_exception;
60 extern pgm_check_handler_t do_dat_exception;
61 extern pgm_check_handler_t do_monitor_call;
62 
63 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
64 
65 #ifndef CONFIG_64BIT
66 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
67 static int kstack_depth_to_print = 12;
68 #else /* CONFIG_64BIT */
69 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
70 static int kstack_depth_to_print = 20;
71 #endif /* CONFIG_64BIT */
72 
73 ATOMIC_NOTIFIER_HEAD(s390die_chain);
74 
75 int register_die_notifier(struct notifier_block *nb)
76 {
77 	return atomic_notifier_chain_register(&s390die_chain, nb);
78 }
79 EXPORT_SYMBOL(register_die_notifier);
80 
81 int unregister_die_notifier(struct notifier_block *nb)
82 {
83 	return atomic_notifier_chain_unregister(&s390die_chain, nb);
84 }
85 EXPORT_SYMBOL(unregister_die_notifier);
86 
87 /*
88  * For show_trace we have tree different stack to consider:
89  *   - the panic stack which is used if the kernel stack has overflown
90  *   - the asynchronous interrupt stack (cpu related)
91  *   - the synchronous kernel stack (process related)
92  * The stack trace can start at any of the three stack and can potentially
93  * touch all of them. The order is: panic stack, async stack, sync stack.
94  */
95 static unsigned long
96 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
97 {
98 	struct stack_frame *sf;
99 	struct pt_regs *regs;
100 
101 	while (1) {
102 		sp = sp & PSW_ADDR_INSN;
103 		if (sp < low || sp > high - sizeof(*sf))
104 			return sp;
105 		sf = (struct stack_frame *) sp;
106 		printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
107 		print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
108 		/* Follow the backchain. */
109 		while (1) {
110 			low = sp;
111 			sp = sf->back_chain & PSW_ADDR_INSN;
112 			if (!sp)
113 				break;
114 			if (sp <= low || sp > high - sizeof(*sf))
115 				return sp;
116 			sf = (struct stack_frame *) sp;
117 			printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
118 			print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
119 		}
120 		/* Zero backchain detected, check for interrupt frame. */
121 		sp = (unsigned long) (sf + 1);
122 		if (sp <= low || sp > high - sizeof(*regs))
123 			return sp;
124 		regs = (struct pt_regs *) sp;
125 		printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
126 		print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
127 		low = sp;
128 		sp = regs->gprs[15];
129 	}
130 }
131 
132 void show_trace(struct task_struct *task, unsigned long *stack)
133 {
134 	register unsigned long __r15 asm ("15");
135 	unsigned long sp;
136 
137 	sp = (unsigned long) stack;
138 	if (!sp)
139 		sp = task ? task->thread.ksp : __r15;
140 	printk("Call Trace:\n");
141 #ifdef CONFIG_CHECK_STACK
142 	sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
143 			  S390_lowcore.panic_stack);
144 #endif
145 	sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
146 			  S390_lowcore.async_stack);
147 	if (task)
148 		__show_trace(sp, (unsigned long) task_stack_page(task),
149 			     (unsigned long) task_stack_page(task) + THREAD_SIZE);
150 	else
151 		__show_trace(sp, S390_lowcore.thread_info,
152 			     S390_lowcore.thread_info + THREAD_SIZE);
153 	printk("\n");
154 	if (!task)
155 		task = current;
156 	debug_show_held_locks(task);
157 }
158 
159 void show_stack(struct task_struct *task, unsigned long *sp)
160 {
161 	register unsigned long * __r15 asm ("15");
162 	unsigned long *stack;
163 	int i;
164 
165 	if (!sp)
166 		stack = task ? (unsigned long *) task->thread.ksp : __r15;
167 	else
168 		stack = sp;
169 
170 	for (i = 0; i < kstack_depth_to_print; i++) {
171 		if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
172 			break;
173 		if (i && ((i * sizeof (long) % 32) == 0))
174 			printk("\n       ");
175 		printk("%p ", (void *)*stack++);
176 	}
177 	printk("\n");
178 	show_trace(task, sp);
179 }
180 
181 /*
182  * The architecture-independent dump_stack generator
183  */
184 void dump_stack(void)
185 {
186 	show_stack(NULL, NULL);
187 }
188 
189 EXPORT_SYMBOL(dump_stack);
190 
191 void show_registers(struct pt_regs *regs)
192 {
193 	mm_segment_t old_fs;
194 	char *mode;
195 	int i;
196 
197 	mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
198 	printk("%s PSW : %p %p",
199 	       mode, (void *) regs->psw.mask,
200 	       (void *) regs->psw.addr);
201 	print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
202 	printk("%s GPRS: " FOURLONG, mode,
203 	       regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
204 	printk("           " FOURLONG,
205 	       regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
206 	printk("           " FOURLONG,
207 	       regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
208 	printk("           " FOURLONG,
209 	       regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
210 
211 #if 0
212 	/* FIXME: this isn't needed any more but it changes the ksymoops
213 	 * input. To remove or not to remove ... */
214 	save_access_regs(regs->acrs);
215 	printk("%s ACRS: %08x %08x %08x %08x\n", mode,
216 	       regs->acrs[0], regs->acrs[1], regs->acrs[2], regs->acrs[3]);
217 	printk("           %08x %08x %08x %08x\n",
218 	       regs->acrs[4], regs->acrs[5], regs->acrs[6], regs->acrs[7]);
219 	printk("           %08x %08x %08x %08x\n",
220 	       regs->acrs[8], regs->acrs[9], regs->acrs[10], regs->acrs[11]);
221 	printk("           %08x %08x %08x %08x\n",
222 	       regs->acrs[12], regs->acrs[13], regs->acrs[14], regs->acrs[15]);
223 #endif
224 
225 	/*
226 	 * Print the first 20 byte of the instruction stream at the
227 	 * time of the fault.
228 	 */
229 	old_fs = get_fs();
230 	if (regs->psw.mask & PSW_MASK_PSTATE)
231 		set_fs(USER_DS);
232 	else
233 		set_fs(KERNEL_DS);
234 	printk("%s Code: ", mode);
235 	for (i = 0; i < 20; i++) {
236 		unsigned char c;
237 		if (__get_user(c, (char __user *)(regs->psw.addr + i))) {
238 			printk(" Bad PSW.");
239 			break;
240 		}
241 		printk("%02x ", c);
242 	}
243 	set_fs(old_fs);
244 
245 	printk("\n");
246 }
247 
248 /* This is called from fs/proc/array.c */
249 char *task_show_regs(struct task_struct *task, char *buffer)
250 {
251 	struct pt_regs *regs;
252 
253 	regs = task_pt_regs(task);
254 	buffer += sprintf(buffer, "task: %p, ksp: %p\n",
255 		       task, (void *)task->thread.ksp);
256 	buffer += sprintf(buffer, "User PSW : %p %p\n",
257 		       (void *) regs->psw.mask, (void *)regs->psw.addr);
258 
259 	buffer += sprintf(buffer, "User GPRS: " FOURLONG,
260 			  regs->gprs[0], regs->gprs[1],
261 			  regs->gprs[2], regs->gprs[3]);
262 	buffer += sprintf(buffer, "           " FOURLONG,
263 			  regs->gprs[4], regs->gprs[5],
264 			  regs->gprs[6], regs->gprs[7]);
265 	buffer += sprintf(buffer, "           " FOURLONG,
266 			  regs->gprs[8], regs->gprs[9],
267 			  regs->gprs[10], regs->gprs[11]);
268 	buffer += sprintf(buffer, "           " FOURLONG,
269 			  regs->gprs[12], regs->gprs[13],
270 			  regs->gprs[14], regs->gprs[15]);
271 	buffer += sprintf(buffer, "User ACRS: %08x %08x %08x %08x\n",
272 			  task->thread.acrs[0], task->thread.acrs[1],
273 			  task->thread.acrs[2], task->thread.acrs[3]);
274 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
275 			  task->thread.acrs[4], task->thread.acrs[5],
276 			  task->thread.acrs[6], task->thread.acrs[7]);
277 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
278 			  task->thread.acrs[8], task->thread.acrs[9],
279 			  task->thread.acrs[10], task->thread.acrs[11]);
280 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
281 			  task->thread.acrs[12], task->thread.acrs[13],
282 			  task->thread.acrs[14], task->thread.acrs[15]);
283 	return buffer;
284 }
285 
286 DEFINE_SPINLOCK(die_lock);
287 
288 void die(const char * str, struct pt_regs * regs, long err)
289 {
290 	static int die_counter;
291 
292 	debug_stop_all();
293 	console_verbose();
294 	spin_lock_irq(&die_lock);
295 	bust_spinlocks(1);
296 	printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
297         show_regs(regs);
298 	bust_spinlocks(0);
299         spin_unlock_irq(&die_lock);
300 	if (in_interrupt())
301 		panic("Fatal exception in interrupt");
302 	if (panic_on_oops)
303 		panic("Fatal exception: panic_on_oops");
304         do_exit(SIGSEGV);
305 }
306 
307 static void inline
308 report_user_fault(long interruption_code, struct pt_regs *regs)
309 {
310 #if defined(CONFIG_SYSCTL)
311 	if (!sysctl_userprocess_debug)
312 		return;
313 #endif
314 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
315 	printk("User process fault: interruption code 0x%lX\n",
316 	       interruption_code);
317 	show_regs(regs);
318 #endif
319 }
320 
321 static void __kprobes inline do_trap(long interruption_code, int signr,
322 					char *str, struct pt_regs *regs,
323 					siginfo_t *info)
324 {
325 	/*
326 	 * We got all needed information from the lowcore and can
327 	 * now safely switch on interrupts.
328 	 */
329         if (regs->psw.mask & PSW_MASK_PSTATE)
330 		local_irq_enable();
331 
332 	if (notify_die(DIE_TRAP, str, regs, interruption_code,
333 				interruption_code, signr) == NOTIFY_STOP)
334 		return;
335 
336         if (regs->psw.mask & PSW_MASK_PSTATE) {
337                 struct task_struct *tsk = current;
338 
339                 tsk->thread.trap_no = interruption_code & 0xffff;
340 		force_sig_info(signr, info, tsk);
341 		report_user_fault(interruption_code, regs);
342         } else {
343                 const struct exception_table_entry *fixup;
344                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
345                 if (fixup)
346                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
347                 else
348                         die(str, regs, interruption_code);
349         }
350 }
351 
352 static inline void __user *get_check_address(struct pt_regs *regs)
353 {
354 	return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
355 }
356 
357 void __kprobes do_single_step(struct pt_regs *regs)
358 {
359 	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
360 					SIGTRAP) == NOTIFY_STOP){
361 		return;
362 	}
363 	if ((current->ptrace & PT_PTRACED) != 0)
364 		force_sig(SIGTRAP, current);
365 }
366 
367 asmlinkage void
368 default_trap_handler(struct pt_regs * regs, long interruption_code)
369 {
370         if (regs->psw.mask & PSW_MASK_PSTATE) {
371 		local_irq_enable();
372 		do_exit(SIGSEGV);
373 		report_user_fault(interruption_code, regs);
374 	} else
375 		die("Unknown program exception", regs, interruption_code);
376 }
377 
378 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
379 asmlinkage void name(struct pt_regs * regs, long interruption_code) \
380 { \
381         siginfo_t info; \
382         info.si_signo = signr; \
383         info.si_errno = 0; \
384         info.si_code = sicode; \
385 	info.si_addr = siaddr; \
386         do_trap(interruption_code, signr, str, regs, &info); \
387 }
388 
389 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
390 	      ILL_ILLADR, get_check_address(regs))
391 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
392 	      ILL_ILLOPN, get_check_address(regs))
393 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
394 	      FPE_INTDIV, get_check_address(regs))
395 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
396 	      FPE_INTOVF, get_check_address(regs))
397 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
398 	      FPE_FLTOVF, get_check_address(regs))
399 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
400 	      FPE_FLTUND, get_check_address(regs))
401 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
402 	      FPE_FLTRES, get_check_address(regs))
403 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
404 	      FPE_FLTDIV, get_check_address(regs))
405 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
406 	      FPE_FLTINV, get_check_address(regs))
407 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
408 	      ILL_ILLOPN, get_check_address(regs))
409 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
410 	      ILL_PRVOPC, get_check_address(regs))
411 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
412 	      ILL_ILLOPN, get_check_address(regs))
413 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
414 	      ILL_ILLOPN, get_check_address(regs))
415 
416 static inline void
417 do_fp_trap(struct pt_regs *regs, void __user *location,
418            int fpc, long interruption_code)
419 {
420 	siginfo_t si;
421 
422 	si.si_signo = SIGFPE;
423 	si.si_errno = 0;
424 	si.si_addr = location;
425 	si.si_code = 0;
426 	/* FPC[2] is Data Exception Code */
427 	if ((fpc & 0x00000300) == 0) {
428 		/* bits 6 and 7 of DXC are 0 iff IEEE exception */
429 		if (fpc & 0x8000) /* invalid fp operation */
430 			si.si_code = FPE_FLTINV;
431 		else if (fpc & 0x4000) /* div by 0 */
432 			si.si_code = FPE_FLTDIV;
433 		else if (fpc & 0x2000) /* overflow */
434 			si.si_code = FPE_FLTOVF;
435 		else if (fpc & 0x1000) /* underflow */
436 			si.si_code = FPE_FLTUND;
437 		else if (fpc & 0x0800) /* inexact */
438 			si.si_code = FPE_FLTRES;
439 	}
440 	current->thread.ieee_instruction_pointer = (addr_t) location;
441 	do_trap(interruption_code, SIGFPE,
442 		"floating point exception", regs, &si);
443 }
444 
445 asmlinkage void illegal_op(struct pt_regs * regs, long interruption_code)
446 {
447 	siginfo_t info;
448         __u8 opcode[6];
449 	__u16 __user *location;
450 	int signal = 0;
451 
452 	location = get_check_address(regs);
453 
454 	/*
455 	 * We got all needed information from the lowcore and can
456 	 * now safely switch on interrupts.
457 	 */
458 	if (regs->psw.mask & PSW_MASK_PSTATE)
459 		local_irq_enable();
460 
461 	if (regs->psw.mask & PSW_MASK_PSTATE) {
462 		if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
463 			return;
464 		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
465 			if (current->ptrace & PT_PTRACED)
466 				force_sig(SIGTRAP, current);
467 			else
468 				signal = SIGILL;
469 #ifdef CONFIG_MATHEMU
470 		} else if (opcode[0] == 0xb3) {
471 			if (get_user(*((__u16 *) (opcode+2)), location+1))
472 				return;
473 			signal = math_emu_b3(opcode, regs);
474                 } else if (opcode[0] == 0xed) {
475 			if (get_user(*((__u32 *) (opcode+2)),
476 				     (__u32 __user *)(location+1)))
477 				return;
478 			signal = math_emu_ed(opcode, regs);
479 		} else if (*((__u16 *) opcode) == 0xb299) {
480 			if (get_user(*((__u16 *) (opcode+2)), location+1))
481 				return;
482 			signal = math_emu_srnm(opcode, regs);
483 		} else if (*((__u16 *) opcode) == 0xb29c) {
484 			if (get_user(*((__u16 *) (opcode+2)), location+1))
485 				return;
486 			signal = math_emu_stfpc(opcode, regs);
487 		} else if (*((__u16 *) opcode) == 0xb29d) {
488 			if (get_user(*((__u16 *) (opcode+2)), location+1))
489 				return;
490 			signal = math_emu_lfpc(opcode, regs);
491 #endif
492 		} else
493 			signal = SIGILL;
494 	} else
495 		signal = SIGILL;
496 
497 #ifdef CONFIG_MATHEMU
498         if (signal == SIGFPE)
499 		do_fp_trap(regs, location,
500                            current->thread.fp_regs.fpc, interruption_code);
501         else if (signal == SIGSEGV) {
502 		info.si_signo = signal;
503 		info.si_errno = 0;
504 		info.si_code = SEGV_MAPERR;
505 		info.si_addr = (void __user *) location;
506 		do_trap(interruption_code, signal,
507 			"user address fault", regs, &info);
508 	} else
509 #endif
510         if (signal) {
511 		info.si_signo = signal;
512 		info.si_errno = 0;
513 		info.si_code = ILL_ILLOPC;
514 		info.si_addr = (void __user *) location;
515 		do_trap(interruption_code, signal,
516 			"illegal operation", regs, &info);
517 	}
518 }
519 
520 
521 #ifdef CONFIG_MATHEMU
522 asmlinkage void
523 specification_exception(struct pt_regs * regs, long interruption_code)
524 {
525         __u8 opcode[6];
526 	__u16 __user *location = NULL;
527 	int signal = 0;
528 
529 	location = (__u16 __user *) get_check_address(regs);
530 
531 	/*
532 	 * We got all needed information from the lowcore and can
533 	 * now safely switch on interrupts.
534 	 */
535         if (regs->psw.mask & PSW_MASK_PSTATE)
536 		local_irq_enable();
537 
538         if (regs->psw.mask & PSW_MASK_PSTATE) {
539 		get_user(*((__u16 *) opcode), location);
540 		switch (opcode[0]) {
541 		case 0x28: /* LDR Rx,Ry   */
542 			signal = math_emu_ldr(opcode);
543 			break;
544 		case 0x38: /* LER Rx,Ry   */
545 			signal = math_emu_ler(opcode);
546 			break;
547 		case 0x60: /* STD R,D(X,B) */
548 			get_user(*((__u16 *) (opcode+2)), location+1);
549 			signal = math_emu_std(opcode, regs);
550 			break;
551 		case 0x68: /* LD R,D(X,B) */
552 			get_user(*((__u16 *) (opcode+2)), location+1);
553 			signal = math_emu_ld(opcode, regs);
554 			break;
555 		case 0x70: /* STE R,D(X,B) */
556 			get_user(*((__u16 *) (opcode+2)), location+1);
557 			signal = math_emu_ste(opcode, regs);
558 			break;
559 		case 0x78: /* LE R,D(X,B) */
560 			get_user(*((__u16 *) (opcode+2)), location+1);
561 			signal = math_emu_le(opcode, regs);
562 			break;
563 		default:
564 			signal = SIGILL;
565 			break;
566                 }
567         } else
568 		signal = SIGILL;
569 
570         if (signal == SIGFPE)
571 		do_fp_trap(regs, location,
572                            current->thread.fp_regs.fpc, interruption_code);
573         else if (signal) {
574 		siginfo_t info;
575 		info.si_signo = signal;
576 		info.si_errno = 0;
577 		info.si_code = ILL_ILLOPN;
578 		info.si_addr = location;
579 		do_trap(interruption_code, signal,
580 			"specification exception", regs, &info);
581 	}
582 }
583 #else
584 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
585 	      ILL_ILLOPN, get_check_address(regs));
586 #endif
587 
588 asmlinkage void data_exception(struct pt_regs * regs, long interruption_code)
589 {
590 	__u16 __user *location;
591 	int signal = 0;
592 
593 	location = get_check_address(regs);
594 
595 	/*
596 	 * We got all needed information from the lowcore and can
597 	 * now safely switch on interrupts.
598 	 */
599 	if (regs->psw.mask & PSW_MASK_PSTATE)
600 		local_irq_enable();
601 
602 	if (MACHINE_HAS_IEEE)
603 		asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
604 
605 #ifdef CONFIG_MATHEMU
606         else if (regs->psw.mask & PSW_MASK_PSTATE) {
607         	__u8 opcode[6];
608 		get_user(*((__u16 *) opcode), location);
609 		switch (opcode[0]) {
610 		case 0x28: /* LDR Rx,Ry   */
611 			signal = math_emu_ldr(opcode);
612 			break;
613 		case 0x38: /* LER Rx,Ry   */
614 			signal = math_emu_ler(opcode);
615 			break;
616 		case 0x60: /* STD R,D(X,B) */
617 			get_user(*((__u16 *) (opcode+2)), location+1);
618 			signal = math_emu_std(opcode, regs);
619 			break;
620 		case 0x68: /* LD R,D(X,B) */
621 			get_user(*((__u16 *) (opcode+2)), location+1);
622 			signal = math_emu_ld(opcode, regs);
623 			break;
624 		case 0x70: /* STE R,D(X,B) */
625 			get_user(*((__u16 *) (opcode+2)), location+1);
626 			signal = math_emu_ste(opcode, regs);
627 			break;
628 		case 0x78: /* LE R,D(X,B) */
629 			get_user(*((__u16 *) (opcode+2)), location+1);
630 			signal = math_emu_le(opcode, regs);
631 			break;
632 		case 0xb3:
633 			get_user(*((__u16 *) (opcode+2)), location+1);
634 			signal = math_emu_b3(opcode, regs);
635 			break;
636                 case 0xed:
637 			get_user(*((__u32 *) (opcode+2)),
638 				 (__u32 __user *)(location+1));
639 			signal = math_emu_ed(opcode, regs);
640 			break;
641 	        case 0xb2:
642 			if (opcode[1] == 0x99) {
643 				get_user(*((__u16 *) (opcode+2)), location+1);
644 				signal = math_emu_srnm(opcode, regs);
645 			} else if (opcode[1] == 0x9c) {
646 				get_user(*((__u16 *) (opcode+2)), location+1);
647 				signal = math_emu_stfpc(opcode, regs);
648 			} else if (opcode[1] == 0x9d) {
649 				get_user(*((__u16 *) (opcode+2)), location+1);
650 				signal = math_emu_lfpc(opcode, regs);
651 			} else
652 				signal = SIGILL;
653 			break;
654 		default:
655 			signal = SIGILL;
656 			break;
657                 }
658         }
659 #endif
660 	if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
661 		signal = SIGFPE;
662 	else
663 		signal = SIGILL;
664         if (signal == SIGFPE)
665 		do_fp_trap(regs, location,
666                            current->thread.fp_regs.fpc, interruption_code);
667         else if (signal) {
668 		siginfo_t info;
669 		info.si_signo = signal;
670 		info.si_errno = 0;
671 		info.si_code = ILL_ILLOPN;
672 		info.si_addr = location;
673 		do_trap(interruption_code, signal,
674 			"data exception", regs, &info);
675 	}
676 }
677 
678 asmlinkage void space_switch_exception(struct pt_regs * regs, long int_code)
679 {
680         siginfo_t info;
681 
682 	/* Set user psw back to home space mode. */
683 	if (regs->psw.mask & PSW_MASK_PSTATE)
684 		regs->psw.mask |= PSW_ASC_HOME;
685 	/* Send SIGILL. */
686         info.si_signo = SIGILL;
687         info.si_errno = 0;
688         info.si_code = ILL_PRVOPC;
689         info.si_addr = get_check_address(regs);
690         do_trap(int_code, SIGILL, "space switch event", regs, &info);
691 }
692 
693 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
694 {
695 	bust_spinlocks(1);
696 	printk("Kernel stack overflow.\n");
697 	show_regs(regs);
698 	bust_spinlocks(0);
699 	panic("Corrupt kernel stack, can't continue.");
700 }
701 
702 /* init is done in lowcore.S and head.S */
703 
704 void __init trap_init(void)
705 {
706         int i;
707 
708         for (i = 0; i < 128; i++)
709           pgm_check_table[i] = &default_trap_handler;
710         pgm_check_table[1] = &illegal_op;
711         pgm_check_table[2] = &privileged_op;
712         pgm_check_table[3] = &execute_exception;
713         pgm_check_table[4] = &do_protection_exception;
714         pgm_check_table[5] = &addressing_exception;
715         pgm_check_table[6] = &specification_exception;
716         pgm_check_table[7] = &data_exception;
717         pgm_check_table[8] = &overflow_exception;
718         pgm_check_table[9] = &divide_exception;
719         pgm_check_table[0x0A] = &overflow_exception;
720         pgm_check_table[0x0B] = &divide_exception;
721         pgm_check_table[0x0C] = &hfp_overflow_exception;
722         pgm_check_table[0x0D] = &hfp_underflow_exception;
723         pgm_check_table[0x0E] = &hfp_significance_exception;
724         pgm_check_table[0x0F] = &hfp_divide_exception;
725         pgm_check_table[0x10] = &do_dat_exception;
726         pgm_check_table[0x11] = &do_dat_exception;
727         pgm_check_table[0x12] = &translation_exception;
728         pgm_check_table[0x13] = &special_op_exception;
729 #ifdef CONFIG_64BIT
730         pgm_check_table[0x38] = &do_dat_exception;
731 	pgm_check_table[0x39] = &do_dat_exception;
732 	pgm_check_table[0x3A] = &do_dat_exception;
733         pgm_check_table[0x3B] = &do_dat_exception;
734 #endif /* CONFIG_64BIT */
735         pgm_check_table[0x15] = &operand_exception;
736         pgm_check_table[0x1C] = &space_switch_exception;
737         pgm_check_table[0x1D] = &hfp_sqrt_exception;
738 	pgm_check_table[0x40] = &do_monitor_call;
739 	pfault_irq_init();
740 }
741