xref: /openbmc/linux/arch/s390/kernel/traps.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 int show_unhandled_signals;
50 
51 extern pgm_check_handler_t do_protection_exception;
52 extern pgm_check_handler_t do_dat_exception;
53 extern pgm_check_handler_t do_asce_exception;
54 
55 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
56 
57 #ifndef CONFIG_64BIT
58 #define LONG "%08lx "
59 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
60 static int kstack_depth_to_print = 12;
61 #else /* CONFIG_64BIT */
62 #define LONG "%016lx "
63 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
64 static int kstack_depth_to_print = 20;
65 #endif /* CONFIG_64BIT */
66 
67 /*
68  * For show_trace we have tree different stack to consider:
69  *   - the panic stack which is used if the kernel stack has overflown
70  *   - the asynchronous interrupt stack (cpu related)
71  *   - the synchronous kernel stack (process related)
72  * The stack trace can start at any of the three stack and can potentially
73  * touch all of them. The order is: panic stack, async stack, sync stack.
74  */
75 static unsigned long
76 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
77 {
78 	struct stack_frame *sf;
79 	struct pt_regs *regs;
80 
81 	while (1) {
82 		sp = sp & PSW_ADDR_INSN;
83 		if (sp < low || sp > high - sizeof(*sf))
84 			return sp;
85 		sf = (struct stack_frame *) sp;
86 		printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
87 		print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
88 		/* Follow the backchain. */
89 		while (1) {
90 			low = sp;
91 			sp = sf->back_chain & PSW_ADDR_INSN;
92 			if (!sp)
93 				break;
94 			if (sp <= low || sp > high - sizeof(*sf))
95 				return sp;
96 			sf = (struct stack_frame *) sp;
97 			printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
98 			print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
99 		}
100 		/* Zero backchain detected, check for interrupt frame. */
101 		sp = (unsigned long) (sf + 1);
102 		if (sp <= low || sp > high - sizeof(*regs))
103 			return sp;
104 		regs = (struct pt_regs *) sp;
105 		printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
106 		print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
107 		low = sp;
108 		sp = regs->gprs[15];
109 	}
110 }
111 
112 static void show_trace(struct task_struct *task, unsigned long *stack)
113 {
114 	register unsigned long __r15 asm ("15");
115 	unsigned long sp;
116 
117 	sp = (unsigned long) stack;
118 	if (!sp)
119 		sp = task ? task->thread.ksp : __r15;
120 	printk("Call Trace:\n");
121 #ifdef CONFIG_CHECK_STACK
122 	sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
123 			  S390_lowcore.panic_stack);
124 #endif
125 	sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
126 			  S390_lowcore.async_stack);
127 	if (task)
128 		__show_trace(sp, (unsigned long) task_stack_page(task),
129 			     (unsigned long) task_stack_page(task) + THREAD_SIZE);
130 	else
131 		__show_trace(sp, S390_lowcore.thread_info,
132 			     S390_lowcore.thread_info + THREAD_SIZE);
133 	if (!task)
134 		task = current;
135 	debug_show_held_locks(task);
136 }
137 
138 void show_stack(struct task_struct *task, unsigned long *sp)
139 {
140 	register unsigned long * __r15 asm ("15");
141 	unsigned long *stack;
142 	int i;
143 
144 	if (!sp)
145 		stack = task ? (unsigned long *) task->thread.ksp : __r15;
146 	else
147 		stack = sp;
148 
149 	for (i = 0; i < kstack_depth_to_print; i++) {
150 		if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
151 			break;
152 		if (i && ((i * sizeof (long) % 32) == 0))
153 			printk("\n       ");
154 		printk(LONG, *stack++);
155 	}
156 	printk("\n");
157 	show_trace(task, sp);
158 }
159 
160 static void show_last_breaking_event(struct pt_regs *regs)
161 {
162 #ifdef CONFIG_64BIT
163 	printk("Last Breaking-Event-Address:\n");
164 	printk(" [<%016lx>] ", regs->args[0] & PSW_ADDR_INSN);
165 	print_symbol("%s\n", regs->args[0] & PSW_ADDR_INSN);
166 #endif
167 }
168 
169 /*
170  * The architecture-independent dump_stack generator
171  */
172 void dump_stack(void)
173 {
174 	printk("CPU: %d %s %s %.*s\n",
175 	       task_thread_info(current)->cpu, print_tainted(),
176 	       init_utsname()->release,
177 	       (int)strcspn(init_utsname()->version, " "),
178 	       init_utsname()->version);
179 	printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
180 	       current->comm, current->pid, current,
181 	       (void *) current->thread.ksp);
182 	show_stack(NULL, NULL);
183 }
184 EXPORT_SYMBOL(dump_stack);
185 
186 static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
187 {
188 	return (regs->psw.mask & bits) / ((~bits + 1) & bits);
189 }
190 
191 void show_registers(struct pt_regs *regs)
192 {
193 	char *mode;
194 
195 	mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
196 	printk("%s PSW : %p %p",
197 	       mode, (void *) regs->psw.mask,
198 	       (void *) regs->psw.addr);
199 	print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
200 	printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
201 	       "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
202 	       mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
203 	       mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
204 	       mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
205 	       mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
206 	       mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
207 #ifdef CONFIG_64BIT
208 	printk(" EA:%x", mask_bits(regs, PSW_BASE_BITS));
209 #endif
210 	printk("\n%s GPRS: " FOURLONG, mode,
211 	       regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
212 	printk("           " FOURLONG,
213 	       regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
214 	printk("           " FOURLONG,
215 	       regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
216 	printk("           " FOURLONG,
217 	       regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
218 
219 	show_code(regs);
220 }
221 
222 void show_regs(struct pt_regs *regs)
223 {
224 	print_modules();
225 	printk("CPU: %d %s %s %.*s\n",
226 	       task_thread_info(current)->cpu, print_tainted(),
227 	       init_utsname()->release,
228 	       (int)strcspn(init_utsname()->version, " "),
229 	       init_utsname()->version);
230 	printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
231 	       current->comm, current->pid, current,
232 	       (void *) current->thread.ksp);
233 	show_registers(regs);
234 	/* Show stack backtrace if pt_regs is from kernel mode */
235 	if (!(regs->psw.mask & PSW_MASK_PSTATE))
236 		show_trace(NULL, (unsigned long *) regs->gprs[15]);
237 	show_last_breaking_event(regs);
238 }
239 
240 /* This is called from fs/proc/array.c */
241 void task_show_regs(struct seq_file *m, struct task_struct *task)
242 {
243 	struct pt_regs *regs;
244 
245 	regs = task_pt_regs(task);
246 	seq_printf(m, "task: %p, ksp: %p\n",
247 		       task, (void *)task->thread.ksp);
248 	seq_printf(m, "User PSW : %p %p\n",
249 		       (void *) regs->psw.mask, (void *)regs->psw.addr);
250 
251 	seq_printf(m, "User GPRS: " FOURLONG,
252 			  regs->gprs[0], regs->gprs[1],
253 			  regs->gprs[2], regs->gprs[3]);
254 	seq_printf(m, "           " FOURLONG,
255 			  regs->gprs[4], regs->gprs[5],
256 			  regs->gprs[6], regs->gprs[7]);
257 	seq_printf(m, "           " FOURLONG,
258 			  regs->gprs[8], regs->gprs[9],
259 			  regs->gprs[10], regs->gprs[11]);
260 	seq_printf(m, "           " FOURLONG,
261 			  regs->gprs[12], regs->gprs[13],
262 			  regs->gprs[14], regs->gprs[15]);
263 	seq_printf(m, "User ACRS: %08x %08x %08x %08x\n",
264 			  task->thread.acrs[0], task->thread.acrs[1],
265 			  task->thread.acrs[2], task->thread.acrs[3]);
266 	seq_printf(m, "           %08x %08x %08x %08x\n",
267 			  task->thread.acrs[4], task->thread.acrs[5],
268 			  task->thread.acrs[6], task->thread.acrs[7]);
269 	seq_printf(m, "           %08x %08x %08x %08x\n",
270 			  task->thread.acrs[8], task->thread.acrs[9],
271 			  task->thread.acrs[10], task->thread.acrs[11]);
272 	seq_printf(m, "           %08x %08x %08x %08x\n",
273 			  task->thread.acrs[12], task->thread.acrs[13],
274 			  task->thread.acrs[14], task->thread.acrs[15]);
275 }
276 
277 static 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 	oops_enter();
284 	debug_stop_all();
285 	console_verbose();
286 	spin_lock_irq(&die_lock);
287 	bust_spinlocks(1);
288 	printk("%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
289 #ifdef CONFIG_PREEMPT
290 	printk("PREEMPT ");
291 #endif
292 #ifdef CONFIG_SMP
293 	printk("SMP ");
294 #endif
295 #ifdef CONFIG_DEBUG_PAGEALLOC
296 	printk("DEBUG_PAGEALLOC");
297 #endif
298 	printk("\n");
299 	notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
300 	show_regs(regs);
301 	bust_spinlocks(0);
302 	add_taint(TAINT_DIE);
303 	spin_unlock_irq(&die_lock);
304 	if (in_interrupt())
305 		panic("Fatal exception in interrupt");
306 	if (panic_on_oops)
307 		panic("Fatal exception: panic_on_oops");
308 	oops_exit();
309 	do_exit(SIGSEGV);
310 }
311 
312 static void inline report_user_fault(struct pt_regs *regs, long int_code,
313 				     int signr)
314 {
315 	if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
316 		return;
317 	if (!unhandled_signal(current, signr))
318 		return;
319 	if (!printk_ratelimit())
320 		return;
321 	printk("User process fault: interruption code 0x%lX ", int_code);
322 	print_vma_addr("in ", regs->psw.addr & PSW_ADDR_INSN);
323 	printk("\n");
324 	show_regs(regs);
325 }
326 
327 int is_valid_bugaddr(unsigned long addr)
328 {
329 	return 1;
330 }
331 
332 static inline void __kprobes do_trap(long pgm_int_code, int signr, char *str,
333 				     struct pt_regs *regs, siginfo_t *info)
334 {
335 	if (notify_die(DIE_TRAP, str, regs, pgm_int_code,
336 		       pgm_int_code, signr) == NOTIFY_STOP)
337 		return;
338 
339         if (regs->psw.mask & PSW_MASK_PSTATE) {
340                 struct task_struct *tsk = current;
341 
342 		tsk->thread.trap_no = pgm_int_code & 0xffff;
343 		force_sig_info(signr, info, tsk);
344 		report_user_fault(regs, pgm_int_code, signr);
345         } else {
346                 const struct exception_table_entry *fixup;
347                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
348                 if (fixup)
349                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
350 		else {
351 			enum bug_trap_type btt;
352 
353 			btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
354 			if (btt == BUG_TRAP_TYPE_WARN)
355 				return;
356 			die(str, regs, pgm_int_code);
357 		}
358         }
359 }
360 
361 static inline void __user *get_psw_address(struct pt_regs *regs,
362 					   long pgm_int_code)
363 {
364 	return (void __user *)
365 		((regs->psw.addr - (pgm_int_code >> 16)) & PSW_ADDR_INSN);
366 }
367 
368 void __kprobes do_single_step(struct pt_regs *regs)
369 {
370 	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
371 					SIGTRAP) == NOTIFY_STOP){
372 		return;
373 	}
374 	if (tracehook_consider_fatal_signal(current, SIGTRAP))
375 		force_sig(SIGTRAP, current);
376 }
377 
378 static void default_trap_handler(struct pt_regs *regs, long pgm_int_code,
379 				 unsigned long trans_exc_code)
380 {
381         if (regs->psw.mask & PSW_MASK_PSTATE) {
382 		report_user_fault(regs, pgm_int_code, SIGSEGV);
383 		do_exit(SIGSEGV);
384 	} else
385 		die("Unknown program exception", regs, pgm_int_code);
386 }
387 
388 #define DO_ERROR_INFO(name, signr, sicode, str) \
389 static void name(struct pt_regs *regs, long pgm_int_code, \
390 		 unsigned long trans_exc_code) \
391 { \
392         siginfo_t info; \
393         info.si_signo = signr; \
394         info.si_errno = 0; \
395         info.si_code = sicode; \
396 	info.si_addr = get_psw_address(regs, pgm_int_code); \
397 	do_trap(pgm_int_code, signr, str, regs, &info);	    \
398 }
399 
400 DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
401 	      "addressing exception")
402 DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
403 	      "execute exception")
404 DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
405 	      "fixpoint divide exception")
406 DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
407 	      "fixpoint overflow exception")
408 DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
409 	      "HFP overflow exception")
410 DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
411 	      "HFP underflow exception")
412 DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
413 	      "HFP significance exception")
414 DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
415 	      "HFP divide exception")
416 DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
417 	      "HFP square root exception")
418 DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
419 	      "operand exception")
420 DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
421 	      "privileged operation")
422 DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
423 	      "special operation exception")
424 DO_ERROR_INFO(translation_exception, SIGILL, ILL_ILLOPN,
425 	      "translation exception")
426 
427 static inline void do_fp_trap(struct pt_regs *regs, void __user *location,
428 			      int fpc, long pgm_int_code)
429 {
430 	siginfo_t si;
431 
432 	si.si_signo = SIGFPE;
433 	si.si_errno = 0;
434 	si.si_addr = location;
435 	si.si_code = 0;
436 	/* FPC[2] is Data Exception Code */
437 	if ((fpc & 0x00000300) == 0) {
438 		/* bits 6 and 7 of DXC are 0 iff IEEE exception */
439 		if (fpc & 0x8000) /* invalid fp operation */
440 			si.si_code = FPE_FLTINV;
441 		else if (fpc & 0x4000) /* div by 0 */
442 			si.si_code = FPE_FLTDIV;
443 		else if (fpc & 0x2000) /* overflow */
444 			si.si_code = FPE_FLTOVF;
445 		else if (fpc & 0x1000) /* underflow */
446 			si.si_code = FPE_FLTUND;
447 		else if (fpc & 0x0800) /* inexact */
448 			si.si_code = FPE_FLTRES;
449 	}
450 	do_trap(pgm_int_code, SIGFPE,
451 		"floating point exception", regs, &si);
452 }
453 
454 static void illegal_op(struct pt_regs *regs, long pgm_int_code,
455 		       unsigned long trans_exc_code)
456 {
457 	siginfo_t info;
458         __u8 opcode[6];
459 	__u16 __user *location;
460 	int signal = 0;
461 
462 	location = get_psw_address(regs, pgm_int_code);
463 
464 	if (regs->psw.mask & PSW_MASK_PSTATE) {
465 		if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
466 			return;
467 		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
468 			if (tracehook_consider_fatal_signal(current, SIGTRAP))
469 				force_sig(SIGTRAP, current);
470 			else
471 				signal = SIGILL;
472 #ifdef CONFIG_MATHEMU
473 		} else if (opcode[0] == 0xb3) {
474 			if (get_user(*((__u16 *) (opcode+2)), location+1))
475 				return;
476 			signal = math_emu_b3(opcode, regs);
477                 } else if (opcode[0] == 0xed) {
478 			if (get_user(*((__u32 *) (opcode+2)),
479 				     (__u32 __user *)(location+1)))
480 				return;
481 			signal = math_emu_ed(opcode, regs);
482 		} else if (*((__u16 *) opcode) == 0xb299) {
483 			if (get_user(*((__u16 *) (opcode+2)), location+1))
484 				return;
485 			signal = math_emu_srnm(opcode, regs);
486 		} else if (*((__u16 *) opcode) == 0xb29c) {
487 			if (get_user(*((__u16 *) (opcode+2)), location+1))
488 				return;
489 			signal = math_emu_stfpc(opcode, regs);
490 		} else if (*((__u16 *) opcode) == 0xb29d) {
491 			if (get_user(*((__u16 *) (opcode+2)), location+1))
492 				return;
493 			signal = math_emu_lfpc(opcode, regs);
494 #endif
495 		} else
496 			signal = SIGILL;
497 	} else {
498 		/*
499 		 * If we get an illegal op in kernel mode, send it through the
500 		 * kprobes notifier. If kprobes doesn't pick it up, SIGILL
501 		 */
502 		if (notify_die(DIE_BPT, "bpt", regs, pgm_int_code,
503 			       3, SIGTRAP) != NOTIFY_STOP)
504 			signal = SIGILL;
505 	}
506 
507 #ifdef CONFIG_MATHEMU
508         if (signal == SIGFPE)
509 		do_fp_trap(regs, location,
510 			   current->thread.fp_regs.fpc, pgm_int_code);
511         else if (signal == SIGSEGV) {
512 		info.si_signo = signal;
513 		info.si_errno = 0;
514 		info.si_code = SEGV_MAPERR;
515 		info.si_addr = (void __user *) location;
516 		do_trap(pgm_int_code, signal,
517 			"user address fault", regs, &info);
518 	} else
519 #endif
520         if (signal) {
521 		info.si_signo = signal;
522 		info.si_errno = 0;
523 		info.si_code = ILL_ILLOPC;
524 		info.si_addr = (void __user *) location;
525 		do_trap(pgm_int_code, signal,
526 			"illegal operation", regs, &info);
527 	}
528 }
529 
530 
531 #ifdef CONFIG_MATHEMU
532 asmlinkage void specification_exception(struct pt_regs *regs,
533 					long pgm_int_code,
534 					unsigned long trans_exc_code)
535 {
536         __u8 opcode[6];
537 	__u16 __user *location = NULL;
538 	int signal = 0;
539 
540 	location = (__u16 __user *) get_psw_address(regs, pgm_int_code);
541 
542         if (regs->psw.mask & PSW_MASK_PSTATE) {
543 		get_user(*((__u16 *) opcode), location);
544 		switch (opcode[0]) {
545 		case 0x28: /* LDR Rx,Ry   */
546 			signal = math_emu_ldr(opcode);
547 			break;
548 		case 0x38: /* LER Rx,Ry   */
549 			signal = math_emu_ler(opcode);
550 			break;
551 		case 0x60: /* STD R,D(X,B) */
552 			get_user(*((__u16 *) (opcode+2)), location+1);
553 			signal = math_emu_std(opcode, regs);
554 			break;
555 		case 0x68: /* LD R,D(X,B) */
556 			get_user(*((__u16 *) (opcode+2)), location+1);
557 			signal = math_emu_ld(opcode, regs);
558 			break;
559 		case 0x70: /* STE R,D(X,B) */
560 			get_user(*((__u16 *) (opcode+2)), location+1);
561 			signal = math_emu_ste(opcode, regs);
562 			break;
563 		case 0x78: /* LE R,D(X,B) */
564 			get_user(*((__u16 *) (opcode+2)), location+1);
565 			signal = math_emu_le(opcode, regs);
566 			break;
567 		default:
568 			signal = SIGILL;
569 			break;
570                 }
571         } else
572 		signal = SIGILL;
573 
574         if (signal == SIGFPE)
575 		do_fp_trap(regs, location,
576 			   current->thread.fp_regs.fpc, pgm_int_code);
577         else if (signal) {
578 		siginfo_t info;
579 		info.si_signo = signal;
580 		info.si_errno = 0;
581 		info.si_code = ILL_ILLOPN;
582 		info.si_addr = location;
583 		do_trap(pgm_int_code, signal,
584 			"specification exception", regs, &info);
585 	}
586 }
587 #else
588 DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
589 	      "specification exception");
590 #endif
591 
592 static void data_exception(struct pt_regs *regs, long pgm_int_code,
593 			   unsigned long trans_exc_code)
594 {
595 	__u16 __user *location;
596 	int signal = 0;
597 
598 	location = get_psw_address(regs, pgm_int_code);
599 
600 	if (MACHINE_HAS_IEEE)
601 		asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
602 
603 #ifdef CONFIG_MATHEMU
604         else if (regs->psw.mask & PSW_MASK_PSTATE) {
605         	__u8 opcode[6];
606 		get_user(*((__u16 *) opcode), location);
607 		switch (opcode[0]) {
608 		case 0x28: /* LDR Rx,Ry   */
609 			signal = math_emu_ldr(opcode);
610 			break;
611 		case 0x38: /* LER Rx,Ry   */
612 			signal = math_emu_ler(opcode);
613 			break;
614 		case 0x60: /* STD R,D(X,B) */
615 			get_user(*((__u16 *) (opcode+2)), location+1);
616 			signal = math_emu_std(opcode, regs);
617 			break;
618 		case 0x68: /* LD R,D(X,B) */
619 			get_user(*((__u16 *) (opcode+2)), location+1);
620 			signal = math_emu_ld(opcode, regs);
621 			break;
622 		case 0x70: /* STE R,D(X,B) */
623 			get_user(*((__u16 *) (opcode+2)), location+1);
624 			signal = math_emu_ste(opcode, regs);
625 			break;
626 		case 0x78: /* LE R,D(X,B) */
627 			get_user(*((__u16 *) (opcode+2)), location+1);
628 			signal = math_emu_le(opcode, regs);
629 			break;
630 		case 0xb3:
631 			get_user(*((__u16 *) (opcode+2)), location+1);
632 			signal = math_emu_b3(opcode, regs);
633 			break;
634                 case 0xed:
635 			get_user(*((__u32 *) (opcode+2)),
636 				 (__u32 __user *)(location+1));
637 			signal = math_emu_ed(opcode, regs);
638 			break;
639 	        case 0xb2:
640 			if (opcode[1] == 0x99) {
641 				get_user(*((__u16 *) (opcode+2)), location+1);
642 				signal = math_emu_srnm(opcode, regs);
643 			} else if (opcode[1] == 0x9c) {
644 				get_user(*((__u16 *) (opcode+2)), location+1);
645 				signal = math_emu_stfpc(opcode, regs);
646 			} else if (opcode[1] == 0x9d) {
647 				get_user(*((__u16 *) (opcode+2)), location+1);
648 				signal = math_emu_lfpc(opcode, regs);
649 			} else
650 				signal = SIGILL;
651 			break;
652 		default:
653 			signal = SIGILL;
654 			break;
655                 }
656         }
657 #endif
658 	if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
659 		signal = SIGFPE;
660 	else
661 		signal = SIGILL;
662         if (signal == SIGFPE)
663 		do_fp_trap(regs, location,
664 			   current->thread.fp_regs.fpc, pgm_int_code);
665         else if (signal) {
666 		siginfo_t info;
667 		info.si_signo = signal;
668 		info.si_errno = 0;
669 		info.si_code = ILL_ILLOPN;
670 		info.si_addr = location;
671 		do_trap(pgm_int_code, signal, "data exception", regs, &info);
672 	}
673 }
674 
675 static void space_switch_exception(struct pt_regs *regs, long pgm_int_code,
676 				   unsigned long trans_exc_code)
677 {
678         siginfo_t info;
679 
680 	/* Set user psw back to home space mode. */
681 	if (regs->psw.mask & PSW_MASK_PSTATE)
682 		regs->psw.mask |= PSW_ASC_HOME;
683 	/* Send SIGILL. */
684         info.si_signo = SIGILL;
685         info.si_errno = 0;
686         info.si_code = ILL_PRVOPC;
687 	info.si_addr = get_psw_address(regs, pgm_int_code);
688 	do_trap(pgm_int_code, SIGILL, "space switch event", regs, &info);
689 }
690 
691 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
692 {
693 	bust_spinlocks(1);
694 	printk("Kernel stack overflow.\n");
695 	show_regs(regs);
696 	bust_spinlocks(0);
697 	panic("Corrupt kernel stack, can't continue.");
698 }
699 
700 /* init is done in lowcore.S and head.S */
701 
702 void __init trap_init(void)
703 {
704         int i;
705 
706         for (i = 0; i < 128; i++)
707           pgm_check_table[i] = &default_trap_handler;
708         pgm_check_table[1] = &illegal_op;
709         pgm_check_table[2] = &privileged_op;
710         pgm_check_table[3] = &execute_exception;
711         pgm_check_table[4] = &do_protection_exception;
712         pgm_check_table[5] = &addressing_exception;
713         pgm_check_table[6] = &specification_exception;
714         pgm_check_table[7] = &data_exception;
715         pgm_check_table[8] = &overflow_exception;
716         pgm_check_table[9] = &divide_exception;
717         pgm_check_table[0x0A] = &overflow_exception;
718         pgm_check_table[0x0B] = &divide_exception;
719         pgm_check_table[0x0C] = &hfp_overflow_exception;
720         pgm_check_table[0x0D] = &hfp_underflow_exception;
721         pgm_check_table[0x0E] = &hfp_significance_exception;
722         pgm_check_table[0x0F] = &hfp_divide_exception;
723         pgm_check_table[0x10] = &do_dat_exception;
724         pgm_check_table[0x11] = &do_dat_exception;
725         pgm_check_table[0x12] = &translation_exception;
726         pgm_check_table[0x13] = &special_op_exception;
727 #ifdef CONFIG_64BIT
728 	pgm_check_table[0x38] = &do_asce_exception;
729 	pgm_check_table[0x39] = &do_dat_exception;
730 	pgm_check_table[0x3A] = &do_dat_exception;
731         pgm_check_table[0x3B] = &do_dat_exception;
732 #endif /* CONFIG_64BIT */
733         pgm_check_table[0x15] = &operand_exception;
734         pgm_check_table[0x1C] = &space_switch_exception;
735         pgm_check_table[0x1D] = &hfp_sqrt_exception;
736 	pfault_irq_init();
737 }
738