xref: /openbmc/linux/arch/s390/kernel/traps.c (revision f42b3800)
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/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 FOURLONG "%08lx %08lx %08lx %08lx\n"
65 static int kstack_depth_to_print = 12;
66 #else /* CONFIG_64BIT */
67 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
68 static int kstack_depth_to_print = 20;
69 #endif /* CONFIG_64BIT */
70 
71 /*
72  * For show_trace we have tree different stack to consider:
73  *   - the panic stack which is used if the kernel stack has overflown
74  *   - the asynchronous interrupt stack (cpu related)
75  *   - the synchronous kernel stack (process related)
76  * The stack trace can start at any of the three stack and can potentially
77  * touch all of them. The order is: panic stack, async stack, sync stack.
78  */
79 static unsigned long
80 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
81 {
82 	struct stack_frame *sf;
83 	struct pt_regs *regs;
84 
85 	while (1) {
86 		sp = sp & PSW_ADDR_INSN;
87 		if (sp < low || sp > high - sizeof(*sf))
88 			return sp;
89 		sf = (struct stack_frame *) sp;
90 		printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
91 		print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
92 		/* Follow the backchain. */
93 		while (1) {
94 			low = sp;
95 			sp = sf->back_chain & PSW_ADDR_INSN;
96 			if (!sp)
97 				break;
98 			if (sp <= low || sp > high - sizeof(*sf))
99 				return sp;
100 			sf = (struct stack_frame *) sp;
101 			printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
102 			print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
103 		}
104 		/* Zero backchain detected, check for interrupt frame. */
105 		sp = (unsigned long) (sf + 1);
106 		if (sp <= low || sp > high - sizeof(*regs))
107 			return sp;
108 		regs = (struct pt_regs *) sp;
109 		printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
110 		print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
111 		low = sp;
112 		sp = regs->gprs[15];
113 	}
114 }
115 
116 void show_trace(struct task_struct *task, unsigned long *stack)
117 {
118 	register unsigned long __r15 asm ("15");
119 	unsigned long sp;
120 
121 	sp = (unsigned long) stack;
122 	if (!sp)
123 		sp = task ? task->thread.ksp : __r15;
124 	printk("Call Trace:\n");
125 #ifdef CONFIG_CHECK_STACK
126 	sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
127 			  S390_lowcore.panic_stack);
128 #endif
129 	sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
130 			  S390_lowcore.async_stack);
131 	if (task)
132 		__show_trace(sp, (unsigned long) task_stack_page(task),
133 			     (unsigned long) task_stack_page(task) + THREAD_SIZE);
134 	else
135 		__show_trace(sp, S390_lowcore.thread_info,
136 			     S390_lowcore.thread_info + THREAD_SIZE);
137 	if (!task)
138 		task = current;
139 	debug_show_held_locks(task);
140 }
141 
142 void show_stack(struct task_struct *task, unsigned long *sp)
143 {
144 	register unsigned long * __r15 asm ("15");
145 	unsigned long *stack;
146 	int i;
147 
148 	if (!sp)
149 		stack = task ? (unsigned long *) task->thread.ksp : __r15;
150 	else
151 		stack = sp;
152 
153 	for (i = 0; i < kstack_depth_to_print; i++) {
154 		if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
155 			break;
156 		if (i && ((i * sizeof (long) % 32) == 0))
157 			printk("\n       ");
158 		printk("%p ", (void *)*stack++);
159 	}
160 	printk("\n");
161 	show_trace(task, sp);
162 }
163 
164 #ifdef CONFIG_64BIT
165 void show_last_breaking_event(struct pt_regs *regs)
166 {
167 	printk("Last Breaking-Event-Address:\n");
168 	printk(" [<%016lx>] ", regs->args[0] & PSW_ADDR_INSN);
169 	print_symbol("%s\n", regs->args[0] & PSW_ADDR_INSN);
170 }
171 #endif
172 
173 /*
174  * The architecture-independent dump_stack generator
175  */
176 void dump_stack(void)
177 {
178 	printk("CPU: %d %s %s %.*s\n",
179 	       task_thread_info(current)->cpu, print_tainted(),
180 	       init_utsname()->release,
181 	       (int)strcspn(init_utsname()->version, " "),
182 	       init_utsname()->version);
183 	printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
184 	       current->comm, current->pid, current,
185 	       (void *) current->thread.ksp);
186 	show_stack(NULL, NULL);
187 }
188 EXPORT_SYMBOL(dump_stack);
189 
190 static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
191 {
192 	return (regs->psw.mask & bits) / ((~bits + 1) & bits);
193 }
194 
195 void show_registers(struct pt_regs *regs)
196 {
197 	char *mode;
198 
199 	mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
200 	printk("%s PSW : %p %p",
201 	       mode, (void *) regs->psw.mask,
202 	       (void *) regs->psw.addr);
203 	print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
204 	printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
205 	       "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
206 	       mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
207 	       mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
208 	       mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
209 	       mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
210 	       mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
211 #ifdef CONFIG_64BIT
212 	printk(" EA:%x", mask_bits(regs, PSW_BASE_BITS));
213 #endif
214 	printk("\n%s GPRS: " FOURLONG, mode,
215 	       regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
216 	printk("           " FOURLONG,
217 	       regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
218 	printk("           " FOURLONG,
219 	       regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
220 	printk("           " FOURLONG,
221 	       regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
222 
223 	show_code(regs);
224 }
225 
226 /* This is called from fs/proc/array.c */
227 void task_show_regs(struct seq_file *m, struct task_struct *task)
228 {
229 	struct pt_regs *regs;
230 
231 	regs = task_pt_regs(task);
232 	seq_printf(m, "task: %p, ksp: %p\n",
233 		       task, (void *)task->thread.ksp);
234 	seq_printf(m, "User PSW : %p %p\n",
235 		       (void *) regs->psw.mask, (void *)regs->psw.addr);
236 
237 	seq_printf(m, "User GPRS: " FOURLONG,
238 			  regs->gprs[0], regs->gprs[1],
239 			  regs->gprs[2], regs->gprs[3]);
240 	seq_printf(m, "           " FOURLONG,
241 			  regs->gprs[4], regs->gprs[5],
242 			  regs->gprs[6], regs->gprs[7]);
243 	seq_printf(m, "           " FOURLONG,
244 			  regs->gprs[8], regs->gprs[9],
245 			  regs->gprs[10], regs->gprs[11]);
246 	seq_printf(m, "           " FOURLONG,
247 			  regs->gprs[12], regs->gprs[13],
248 			  regs->gprs[14], regs->gprs[15]);
249 	seq_printf(m, "User ACRS: %08x %08x %08x %08x\n",
250 			  task->thread.acrs[0], task->thread.acrs[1],
251 			  task->thread.acrs[2], task->thread.acrs[3]);
252 	seq_printf(m, "           %08x %08x %08x %08x\n",
253 			  task->thread.acrs[4], task->thread.acrs[5],
254 			  task->thread.acrs[6], task->thread.acrs[7]);
255 	seq_printf(m, "           %08x %08x %08x %08x\n",
256 			  task->thread.acrs[8], task->thread.acrs[9],
257 			  task->thread.acrs[10], task->thread.acrs[11]);
258 	seq_printf(m, "           %08x %08x %08x %08x\n",
259 			  task->thread.acrs[12], task->thread.acrs[13],
260 			  task->thread.acrs[14], task->thread.acrs[15]);
261 }
262 
263 static DEFINE_SPINLOCK(die_lock);
264 
265 void die(const char * str, struct pt_regs * regs, long err)
266 {
267 	static int die_counter;
268 
269 	oops_enter();
270 	debug_stop_all();
271 	console_verbose();
272 	spin_lock_irq(&die_lock);
273 	bust_spinlocks(1);
274 	printk("%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
275 #ifdef CONFIG_PREEMPT
276 	printk("PREEMPT ");
277 #endif
278 #ifdef CONFIG_SMP
279 	printk("SMP ");
280 #endif
281 #ifdef CONFIG_DEBUG_PAGEALLOC
282 	printk("DEBUG_PAGEALLOC");
283 #endif
284 	printk("\n");
285 	notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
286 	show_regs(regs);
287 	bust_spinlocks(0);
288 	add_taint(TAINT_DIE);
289 	spin_unlock_irq(&die_lock);
290 	if (in_interrupt())
291 		panic("Fatal exception in interrupt");
292 	if (panic_on_oops)
293 		panic("Fatal exception: panic_on_oops");
294 	oops_exit();
295 	do_exit(SIGSEGV);
296 }
297 
298 static void inline
299 report_user_fault(long interruption_code, struct pt_regs *regs)
300 {
301 #if defined(CONFIG_SYSCTL)
302 	if (!sysctl_userprocess_debug)
303 		return;
304 #endif
305 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
306 	printk("User process fault: interruption code 0x%lX\n",
307 	       interruption_code);
308 	show_regs(regs);
309 #endif
310 }
311 
312 int is_valid_bugaddr(unsigned long addr)
313 {
314 	return 1;
315 }
316 
317 static void __kprobes inline do_trap(long interruption_code, int signr,
318 					char *str, struct pt_regs *regs,
319 					siginfo_t *info)
320 {
321 	/*
322 	 * We got all needed information from the lowcore and can
323 	 * now safely switch on interrupts.
324 	 */
325         if (regs->psw.mask & PSW_MASK_PSTATE)
326 		local_irq_enable();
327 
328 	if (notify_die(DIE_TRAP, str, regs, interruption_code,
329 				interruption_code, signr) == NOTIFY_STOP)
330 		return;
331 
332         if (regs->psw.mask & PSW_MASK_PSTATE) {
333                 struct task_struct *tsk = current;
334 
335                 tsk->thread.trap_no = interruption_code & 0xffff;
336 		force_sig_info(signr, info, tsk);
337 		report_user_fault(interruption_code, regs);
338         } else {
339                 const struct exception_table_entry *fixup;
340                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
341                 if (fixup)
342                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
343 		else {
344 			enum bug_trap_type btt;
345 
346 			btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
347 			if (btt == BUG_TRAP_TYPE_WARN)
348 				return;
349 			die(str, regs, interruption_code);
350 		}
351         }
352 }
353 
354 static inline void __user *get_check_address(struct pt_regs *regs)
355 {
356 	return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
357 }
358 
359 void __kprobes do_single_step(struct pt_regs *regs)
360 {
361 	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
362 					SIGTRAP) == NOTIFY_STOP){
363 		return;
364 	}
365 	if ((current->ptrace & PT_PTRACED) != 0)
366 		force_sig(SIGTRAP, current);
367 }
368 
369 static void default_trap_handler(struct pt_regs * regs, long interruption_code)
370 {
371         if (regs->psw.mask & PSW_MASK_PSTATE) {
372 		local_irq_enable();
373 		do_exit(SIGSEGV);
374 		report_user_fault(interruption_code, regs);
375 	} else
376 		die("Unknown program exception", regs, interruption_code);
377 }
378 
379 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
380 static void name(struct pt_regs * regs, long interruption_code) \
381 { \
382         siginfo_t info; \
383         info.si_signo = signr; \
384         info.si_errno = 0; \
385         info.si_code = sicode; \
386 	info.si_addr = siaddr; \
387         do_trap(interruption_code, signr, str, regs, &info); \
388 }
389 
390 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
391 	      ILL_ILLADR, get_check_address(regs))
392 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
393 	      ILL_ILLOPN, get_check_address(regs))
394 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
395 	      FPE_INTDIV, get_check_address(regs))
396 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
397 	      FPE_INTOVF, get_check_address(regs))
398 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
399 	      FPE_FLTOVF, get_check_address(regs))
400 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
401 	      FPE_FLTUND, get_check_address(regs))
402 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
403 	      FPE_FLTRES, get_check_address(regs))
404 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
405 	      FPE_FLTDIV, get_check_address(regs))
406 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
407 	      FPE_FLTINV, get_check_address(regs))
408 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
409 	      ILL_ILLOPN, get_check_address(regs))
410 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
411 	      ILL_PRVOPC, get_check_address(regs))
412 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
413 	      ILL_ILLOPN, get_check_address(regs))
414 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
415 	      ILL_ILLOPN, get_check_address(regs))
416 
417 static inline void
418 do_fp_trap(struct pt_regs *regs, void __user *location,
419            int fpc, long interruption_code)
420 {
421 	siginfo_t si;
422 
423 	si.si_signo = SIGFPE;
424 	si.si_errno = 0;
425 	si.si_addr = location;
426 	si.si_code = 0;
427 	/* FPC[2] is Data Exception Code */
428 	if ((fpc & 0x00000300) == 0) {
429 		/* bits 6 and 7 of DXC are 0 iff IEEE exception */
430 		if (fpc & 0x8000) /* invalid fp operation */
431 			si.si_code = FPE_FLTINV;
432 		else if (fpc & 0x4000) /* div by 0 */
433 			si.si_code = FPE_FLTDIV;
434 		else if (fpc & 0x2000) /* overflow */
435 			si.si_code = FPE_FLTOVF;
436 		else if (fpc & 0x1000) /* underflow */
437 			si.si_code = FPE_FLTUND;
438 		else if (fpc & 0x0800) /* inexact */
439 			si.si_code = FPE_FLTRES;
440 	}
441 	current->thread.ieee_instruction_pointer = (addr_t) location;
442 	do_trap(interruption_code, SIGFPE,
443 		"floating point exception", regs, &si);
444 }
445 
446 static void illegal_op(struct pt_regs * regs, long interruption_code)
447 {
448 	siginfo_t info;
449         __u8 opcode[6];
450 	__u16 __user *location;
451 	int signal = 0;
452 
453 	location = get_check_address(regs);
454 
455 	/*
456 	 * We got all needed information from the lowcore and can
457 	 * now safely switch on interrupts.
458 	 */
459 	if (regs->psw.mask & PSW_MASK_PSTATE)
460 		local_irq_enable();
461 
462 	if (regs->psw.mask & PSW_MASK_PSTATE) {
463 		if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
464 			return;
465 		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
466 			if (current->ptrace & PT_PTRACED)
467 				force_sig(SIGTRAP, current);
468 			else
469 				signal = SIGILL;
470 #ifdef CONFIG_MATHEMU
471 		} else if (opcode[0] == 0xb3) {
472 			if (get_user(*((__u16 *) (opcode+2)), location+1))
473 				return;
474 			signal = math_emu_b3(opcode, regs);
475                 } else if (opcode[0] == 0xed) {
476 			if (get_user(*((__u32 *) (opcode+2)),
477 				     (__u32 __user *)(location+1)))
478 				return;
479 			signal = math_emu_ed(opcode, regs);
480 		} else if (*((__u16 *) opcode) == 0xb299) {
481 			if (get_user(*((__u16 *) (opcode+2)), location+1))
482 				return;
483 			signal = math_emu_srnm(opcode, regs);
484 		} else if (*((__u16 *) opcode) == 0xb29c) {
485 			if (get_user(*((__u16 *) (opcode+2)), location+1))
486 				return;
487 			signal = math_emu_stfpc(opcode, regs);
488 		} else if (*((__u16 *) opcode) == 0xb29d) {
489 			if (get_user(*((__u16 *) (opcode+2)), location+1))
490 				return;
491 			signal = math_emu_lfpc(opcode, regs);
492 #endif
493 		} else
494 			signal = SIGILL;
495 	} else {
496 		/*
497 		 * If we get an illegal op in kernel mode, send it through the
498 		 * kprobes notifier. If kprobes doesn't pick it up, SIGILL
499 		 */
500 		if (notify_die(DIE_BPT, "bpt", regs, interruption_code,
501 			       3, SIGTRAP) != NOTIFY_STOP)
502 			signal = SIGILL;
503 	}
504 
505 #ifdef CONFIG_MATHEMU
506         if (signal == SIGFPE)
507 		do_fp_trap(regs, location,
508                            current->thread.fp_regs.fpc, interruption_code);
509         else if (signal == SIGSEGV) {
510 		info.si_signo = signal;
511 		info.si_errno = 0;
512 		info.si_code = SEGV_MAPERR;
513 		info.si_addr = (void __user *) location;
514 		do_trap(interruption_code, signal,
515 			"user address fault", regs, &info);
516 	} else
517 #endif
518         if (signal) {
519 		info.si_signo = signal;
520 		info.si_errno = 0;
521 		info.si_code = ILL_ILLOPC;
522 		info.si_addr = (void __user *) location;
523 		do_trap(interruption_code, signal,
524 			"illegal operation", regs, &info);
525 	}
526 }
527 
528 
529 #ifdef CONFIG_MATHEMU
530 asmlinkage void
531 specification_exception(struct pt_regs * regs, long interruption_code)
532 {
533         __u8 opcode[6];
534 	__u16 __user *location = NULL;
535 	int signal = 0;
536 
537 	location = (__u16 __user *) get_check_address(regs);
538 
539 	/*
540 	 * We got all needed information from the lowcore and can
541 	 * now safely switch on interrupts.
542 	 */
543         if (regs->psw.mask & PSW_MASK_PSTATE)
544 		local_irq_enable();
545 
546         if (regs->psw.mask & PSW_MASK_PSTATE) {
547 		get_user(*((__u16 *) opcode), location);
548 		switch (opcode[0]) {
549 		case 0x28: /* LDR Rx,Ry   */
550 			signal = math_emu_ldr(opcode);
551 			break;
552 		case 0x38: /* LER Rx,Ry   */
553 			signal = math_emu_ler(opcode);
554 			break;
555 		case 0x60: /* STD R,D(X,B) */
556 			get_user(*((__u16 *) (opcode+2)), location+1);
557 			signal = math_emu_std(opcode, regs);
558 			break;
559 		case 0x68: /* LD R,D(X,B) */
560 			get_user(*((__u16 *) (opcode+2)), location+1);
561 			signal = math_emu_ld(opcode, regs);
562 			break;
563 		case 0x70: /* STE R,D(X,B) */
564 			get_user(*((__u16 *) (opcode+2)), location+1);
565 			signal = math_emu_ste(opcode, regs);
566 			break;
567 		case 0x78: /* LE R,D(X,B) */
568 			get_user(*((__u16 *) (opcode+2)), location+1);
569 			signal = math_emu_le(opcode, regs);
570 			break;
571 		default:
572 			signal = SIGILL;
573 			break;
574                 }
575         } else
576 		signal = SIGILL;
577 
578         if (signal == SIGFPE)
579 		do_fp_trap(regs, location,
580                            current->thread.fp_regs.fpc, interruption_code);
581         else if (signal) {
582 		siginfo_t info;
583 		info.si_signo = signal;
584 		info.si_errno = 0;
585 		info.si_code = ILL_ILLOPN;
586 		info.si_addr = location;
587 		do_trap(interruption_code, signal,
588 			"specification exception", regs, &info);
589 	}
590 }
591 #else
592 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
593 	      ILL_ILLOPN, get_check_address(regs));
594 #endif
595 
596 static void data_exception(struct pt_regs * regs, long interruption_code)
597 {
598 	__u16 __user *location;
599 	int signal = 0;
600 
601 	location = get_check_address(regs);
602 
603 	/*
604 	 * We got all needed information from the lowcore and can
605 	 * now safely switch on interrupts.
606 	 */
607 	if (regs->psw.mask & PSW_MASK_PSTATE)
608 		local_irq_enable();
609 
610 	if (MACHINE_HAS_IEEE)
611 		asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
612 
613 #ifdef CONFIG_MATHEMU
614         else if (regs->psw.mask & PSW_MASK_PSTATE) {
615         	__u8 opcode[6];
616 		get_user(*((__u16 *) opcode), location);
617 		switch (opcode[0]) {
618 		case 0x28: /* LDR Rx,Ry   */
619 			signal = math_emu_ldr(opcode);
620 			break;
621 		case 0x38: /* LER Rx,Ry   */
622 			signal = math_emu_ler(opcode);
623 			break;
624 		case 0x60: /* STD R,D(X,B) */
625 			get_user(*((__u16 *) (opcode+2)), location+1);
626 			signal = math_emu_std(opcode, regs);
627 			break;
628 		case 0x68: /* LD R,D(X,B) */
629 			get_user(*((__u16 *) (opcode+2)), location+1);
630 			signal = math_emu_ld(opcode, regs);
631 			break;
632 		case 0x70: /* STE R,D(X,B) */
633 			get_user(*((__u16 *) (opcode+2)), location+1);
634 			signal = math_emu_ste(opcode, regs);
635 			break;
636 		case 0x78: /* LE R,D(X,B) */
637 			get_user(*((__u16 *) (opcode+2)), location+1);
638 			signal = math_emu_le(opcode, regs);
639 			break;
640 		case 0xb3:
641 			get_user(*((__u16 *) (opcode+2)), location+1);
642 			signal = math_emu_b3(opcode, regs);
643 			break;
644                 case 0xed:
645 			get_user(*((__u32 *) (opcode+2)),
646 				 (__u32 __user *)(location+1));
647 			signal = math_emu_ed(opcode, regs);
648 			break;
649 	        case 0xb2:
650 			if (opcode[1] == 0x99) {
651 				get_user(*((__u16 *) (opcode+2)), location+1);
652 				signal = math_emu_srnm(opcode, regs);
653 			} else if (opcode[1] == 0x9c) {
654 				get_user(*((__u16 *) (opcode+2)), location+1);
655 				signal = math_emu_stfpc(opcode, regs);
656 			} else if (opcode[1] == 0x9d) {
657 				get_user(*((__u16 *) (opcode+2)), location+1);
658 				signal = math_emu_lfpc(opcode, regs);
659 			} else
660 				signal = SIGILL;
661 			break;
662 		default:
663 			signal = SIGILL;
664 			break;
665                 }
666         }
667 #endif
668 	if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
669 		signal = SIGFPE;
670 	else
671 		signal = SIGILL;
672         if (signal == SIGFPE)
673 		do_fp_trap(regs, location,
674                            current->thread.fp_regs.fpc, interruption_code);
675         else if (signal) {
676 		siginfo_t info;
677 		info.si_signo = signal;
678 		info.si_errno = 0;
679 		info.si_code = ILL_ILLOPN;
680 		info.si_addr = location;
681 		do_trap(interruption_code, signal,
682 			"data exception", regs, &info);
683 	}
684 }
685 
686 static void space_switch_exception(struct pt_regs * regs, long int_code)
687 {
688         siginfo_t info;
689 
690 	/* Set user psw back to home space mode. */
691 	if (regs->psw.mask & PSW_MASK_PSTATE)
692 		regs->psw.mask |= PSW_ASC_HOME;
693 	/* Send SIGILL. */
694         info.si_signo = SIGILL;
695         info.si_errno = 0;
696         info.si_code = ILL_PRVOPC;
697         info.si_addr = get_check_address(regs);
698         do_trap(int_code, SIGILL, "space switch event", regs, &info);
699 }
700 
701 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
702 {
703 	bust_spinlocks(1);
704 	printk("Kernel stack overflow.\n");
705 	show_regs(regs);
706 	bust_spinlocks(0);
707 	panic("Corrupt kernel stack, can't continue.");
708 }
709 
710 /* init is done in lowcore.S and head.S */
711 
712 void __init trap_init(void)
713 {
714         int i;
715 
716         for (i = 0; i < 128; i++)
717           pgm_check_table[i] = &default_trap_handler;
718         pgm_check_table[1] = &illegal_op;
719         pgm_check_table[2] = &privileged_op;
720         pgm_check_table[3] = &execute_exception;
721         pgm_check_table[4] = &do_protection_exception;
722         pgm_check_table[5] = &addressing_exception;
723         pgm_check_table[6] = &specification_exception;
724         pgm_check_table[7] = &data_exception;
725         pgm_check_table[8] = &overflow_exception;
726         pgm_check_table[9] = &divide_exception;
727         pgm_check_table[0x0A] = &overflow_exception;
728         pgm_check_table[0x0B] = &divide_exception;
729         pgm_check_table[0x0C] = &hfp_overflow_exception;
730         pgm_check_table[0x0D] = &hfp_underflow_exception;
731         pgm_check_table[0x0E] = &hfp_significance_exception;
732         pgm_check_table[0x0F] = &hfp_divide_exception;
733         pgm_check_table[0x10] = &do_dat_exception;
734         pgm_check_table[0x11] = &do_dat_exception;
735         pgm_check_table[0x12] = &translation_exception;
736         pgm_check_table[0x13] = &special_op_exception;
737 #ifdef CONFIG_64BIT
738 	pgm_check_table[0x38] = &do_asce_exception;
739 	pgm_check_table[0x39] = &do_dat_exception;
740 	pgm_check_table[0x3A] = &do_dat_exception;
741         pgm_check_table[0x3B] = &do_dat_exception;
742 #endif /* CONFIG_64BIT */
743         pgm_check_table[0x15] = &operand_exception;
744         pgm_check_table[0x1C] = &space_switch_exception;
745         pgm_check_table[0x1D] = &hfp_sqrt_exception;
746 	pfault_irq_init();
747 }
748