xref: /openbmc/linux/arch/s390/kernel/traps.c (revision 8569c914)
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 static 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 static void show_last_breaking_event(struct pt_regs *regs)
165 {
166 #ifdef CONFIG_64BIT
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 #endif
171 }
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 void show_regs(struct pt_regs *regs)
227 {
228 	print_modules();
229 	printk("CPU: %d %s %s %.*s\n",
230 	       task_thread_info(current)->cpu, print_tainted(),
231 	       init_utsname()->release,
232 	       (int)strcspn(init_utsname()->version, " "),
233 	       init_utsname()->version);
234 	printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
235 	       current->comm, current->pid, current,
236 	       (void *) current->thread.ksp);
237 	show_registers(regs);
238 	/* Show stack backtrace if pt_regs is from kernel mode */
239 	if (!(regs->psw.mask & PSW_MASK_PSTATE))
240 		show_trace(NULL, (unsigned long *) regs->gprs[15]);
241 	show_last_breaking_event(regs);
242 }
243 
244 /* This is called from fs/proc/array.c */
245 void task_show_regs(struct seq_file *m, struct task_struct *task)
246 {
247 	struct pt_regs *regs;
248 
249 	regs = task_pt_regs(task);
250 	seq_printf(m, "task: %p, ksp: %p\n",
251 		       task, (void *)task->thread.ksp);
252 	seq_printf(m, "User PSW : %p %p\n",
253 		       (void *) regs->psw.mask, (void *)regs->psw.addr);
254 
255 	seq_printf(m, "User GPRS: " FOURLONG,
256 			  regs->gprs[0], regs->gprs[1],
257 			  regs->gprs[2], regs->gprs[3]);
258 	seq_printf(m, "           " FOURLONG,
259 			  regs->gprs[4], regs->gprs[5],
260 			  regs->gprs[6], regs->gprs[7]);
261 	seq_printf(m, "           " FOURLONG,
262 			  regs->gprs[8], regs->gprs[9],
263 			  regs->gprs[10], regs->gprs[11]);
264 	seq_printf(m, "           " FOURLONG,
265 			  regs->gprs[12], regs->gprs[13],
266 			  regs->gprs[14], regs->gprs[15]);
267 	seq_printf(m, "User ACRS: %08x %08x %08x %08x\n",
268 			  task->thread.acrs[0], task->thread.acrs[1],
269 			  task->thread.acrs[2], task->thread.acrs[3]);
270 	seq_printf(m, "           %08x %08x %08x %08x\n",
271 			  task->thread.acrs[4], task->thread.acrs[5],
272 			  task->thread.acrs[6], task->thread.acrs[7]);
273 	seq_printf(m, "           %08x %08x %08x %08x\n",
274 			  task->thread.acrs[8], task->thread.acrs[9],
275 			  task->thread.acrs[10], task->thread.acrs[11]);
276 	seq_printf(m, "           %08x %08x %08x %08x\n",
277 			  task->thread.acrs[12], task->thread.acrs[13],
278 			  task->thread.acrs[14], task->thread.acrs[15]);
279 }
280 
281 static DEFINE_SPINLOCK(die_lock);
282 
283 void die(const char * str, struct pt_regs * regs, long err)
284 {
285 	static int die_counter;
286 
287 	oops_enter();
288 	debug_stop_all();
289 	console_verbose();
290 	spin_lock_irq(&die_lock);
291 	bust_spinlocks(1);
292 	printk("%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
293 #ifdef CONFIG_PREEMPT
294 	printk("PREEMPT ");
295 #endif
296 #ifdef CONFIG_SMP
297 	printk("SMP ");
298 #endif
299 #ifdef CONFIG_DEBUG_PAGEALLOC
300 	printk("DEBUG_PAGEALLOC");
301 #endif
302 	printk("\n");
303 	notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
304 	show_regs(regs);
305 	bust_spinlocks(0);
306 	add_taint(TAINT_DIE);
307 	spin_unlock_irq(&die_lock);
308 	if (in_interrupt())
309 		panic("Fatal exception in interrupt");
310 	if (panic_on_oops)
311 		panic("Fatal exception: panic_on_oops");
312 	oops_exit();
313 	do_exit(SIGSEGV);
314 }
315 
316 static void inline
317 report_user_fault(long interruption_code, struct pt_regs *regs)
318 {
319 #if defined(CONFIG_SYSCTL)
320 	if (!sysctl_userprocess_debug)
321 		return;
322 #endif
323 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
324 	printk("User process fault: interruption code 0x%lX\n",
325 	       interruption_code);
326 	show_regs(regs);
327 #endif
328 }
329 
330 int is_valid_bugaddr(unsigned long addr)
331 {
332 	return 1;
333 }
334 
335 static void __kprobes inline do_trap(long interruption_code, int signr,
336 					char *str, struct pt_regs *regs,
337 					siginfo_t *info)
338 {
339 	/*
340 	 * We got all needed information from the lowcore and can
341 	 * now safely switch on interrupts.
342 	 */
343         if (regs->psw.mask & PSW_MASK_PSTATE)
344 		local_irq_enable();
345 
346 	if (notify_die(DIE_TRAP, str, regs, interruption_code,
347 				interruption_code, signr) == NOTIFY_STOP)
348 		return;
349 
350         if (regs->psw.mask & PSW_MASK_PSTATE) {
351                 struct task_struct *tsk = current;
352 
353                 tsk->thread.trap_no = interruption_code & 0xffff;
354 		force_sig_info(signr, info, tsk);
355 		report_user_fault(interruption_code, regs);
356         } else {
357                 const struct exception_table_entry *fixup;
358                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
359                 if (fixup)
360                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
361 		else {
362 			enum bug_trap_type btt;
363 
364 			btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
365 			if (btt == BUG_TRAP_TYPE_WARN)
366 				return;
367 			die(str, regs, interruption_code);
368 		}
369         }
370 }
371 
372 static inline void __user *get_check_address(struct pt_regs *regs)
373 {
374 	return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
375 }
376 
377 void __kprobes do_single_step(struct pt_regs *regs)
378 {
379 	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
380 					SIGTRAP) == NOTIFY_STOP){
381 		return;
382 	}
383 	if ((current->ptrace & PT_PTRACED) != 0)
384 		force_sig(SIGTRAP, current);
385 }
386 
387 static void default_trap_handler(struct pt_regs * regs, long interruption_code)
388 {
389         if (regs->psw.mask & PSW_MASK_PSTATE) {
390 		local_irq_enable();
391 		do_exit(SIGSEGV);
392 		report_user_fault(interruption_code, regs);
393 	} else
394 		die("Unknown program exception", regs, interruption_code);
395 }
396 
397 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
398 static void name(struct pt_regs * regs, long interruption_code) \
399 { \
400         siginfo_t info; \
401         info.si_signo = signr; \
402         info.si_errno = 0; \
403         info.si_code = sicode; \
404 	info.si_addr = siaddr; \
405         do_trap(interruption_code, signr, str, regs, &info); \
406 }
407 
408 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
409 	      ILL_ILLADR, get_check_address(regs))
410 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
411 	      ILL_ILLOPN, get_check_address(regs))
412 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
413 	      FPE_INTDIV, get_check_address(regs))
414 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
415 	      FPE_INTOVF, get_check_address(regs))
416 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
417 	      FPE_FLTOVF, get_check_address(regs))
418 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
419 	      FPE_FLTUND, get_check_address(regs))
420 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
421 	      FPE_FLTRES, get_check_address(regs))
422 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
423 	      FPE_FLTDIV, get_check_address(regs))
424 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
425 	      FPE_FLTINV, get_check_address(regs))
426 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
427 	      ILL_ILLOPN, get_check_address(regs))
428 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
429 	      ILL_PRVOPC, get_check_address(regs))
430 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
431 	      ILL_ILLOPN, get_check_address(regs))
432 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
433 	      ILL_ILLOPN, get_check_address(regs))
434 
435 static inline void
436 do_fp_trap(struct pt_regs *regs, void __user *location,
437            int fpc, long interruption_code)
438 {
439 	siginfo_t si;
440 
441 	si.si_signo = SIGFPE;
442 	si.si_errno = 0;
443 	si.si_addr = location;
444 	si.si_code = 0;
445 	/* FPC[2] is Data Exception Code */
446 	if ((fpc & 0x00000300) == 0) {
447 		/* bits 6 and 7 of DXC are 0 iff IEEE exception */
448 		if (fpc & 0x8000) /* invalid fp operation */
449 			si.si_code = FPE_FLTINV;
450 		else if (fpc & 0x4000) /* div by 0 */
451 			si.si_code = FPE_FLTDIV;
452 		else if (fpc & 0x2000) /* overflow */
453 			si.si_code = FPE_FLTOVF;
454 		else if (fpc & 0x1000) /* underflow */
455 			si.si_code = FPE_FLTUND;
456 		else if (fpc & 0x0800) /* inexact */
457 			si.si_code = FPE_FLTRES;
458 	}
459 	current->thread.ieee_instruction_pointer = (addr_t) location;
460 	do_trap(interruption_code, SIGFPE,
461 		"floating point exception", regs, &si);
462 }
463 
464 static void illegal_op(struct pt_regs * regs, long interruption_code)
465 {
466 	siginfo_t info;
467         __u8 opcode[6];
468 	__u16 __user *location;
469 	int signal = 0;
470 
471 	location = get_check_address(regs);
472 
473 	/*
474 	 * We got all needed information from the lowcore and can
475 	 * now safely switch on interrupts.
476 	 */
477 	if (regs->psw.mask & PSW_MASK_PSTATE)
478 		local_irq_enable();
479 
480 	if (regs->psw.mask & PSW_MASK_PSTATE) {
481 		if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
482 			return;
483 		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
484 			if (current->ptrace & PT_PTRACED)
485 				force_sig(SIGTRAP, current);
486 			else
487 				signal = SIGILL;
488 #ifdef CONFIG_MATHEMU
489 		} else if (opcode[0] == 0xb3) {
490 			if (get_user(*((__u16 *) (opcode+2)), location+1))
491 				return;
492 			signal = math_emu_b3(opcode, regs);
493                 } else if (opcode[0] == 0xed) {
494 			if (get_user(*((__u32 *) (opcode+2)),
495 				     (__u32 __user *)(location+1)))
496 				return;
497 			signal = math_emu_ed(opcode, regs);
498 		} else if (*((__u16 *) opcode) == 0xb299) {
499 			if (get_user(*((__u16 *) (opcode+2)), location+1))
500 				return;
501 			signal = math_emu_srnm(opcode, regs);
502 		} else if (*((__u16 *) opcode) == 0xb29c) {
503 			if (get_user(*((__u16 *) (opcode+2)), location+1))
504 				return;
505 			signal = math_emu_stfpc(opcode, regs);
506 		} else if (*((__u16 *) opcode) == 0xb29d) {
507 			if (get_user(*((__u16 *) (opcode+2)), location+1))
508 				return;
509 			signal = math_emu_lfpc(opcode, regs);
510 #endif
511 		} else
512 			signal = SIGILL;
513 	} else {
514 		/*
515 		 * If we get an illegal op in kernel mode, send it through the
516 		 * kprobes notifier. If kprobes doesn't pick it up, SIGILL
517 		 */
518 		if (notify_die(DIE_BPT, "bpt", regs, interruption_code,
519 			       3, SIGTRAP) != NOTIFY_STOP)
520 			signal = SIGILL;
521 	}
522 
523 #ifdef CONFIG_MATHEMU
524         if (signal == SIGFPE)
525 		do_fp_trap(regs, location,
526                            current->thread.fp_regs.fpc, interruption_code);
527         else if (signal == SIGSEGV) {
528 		info.si_signo = signal;
529 		info.si_errno = 0;
530 		info.si_code = SEGV_MAPERR;
531 		info.si_addr = (void __user *) location;
532 		do_trap(interruption_code, signal,
533 			"user address fault", regs, &info);
534 	} else
535 #endif
536         if (signal) {
537 		info.si_signo = signal;
538 		info.si_errno = 0;
539 		info.si_code = ILL_ILLOPC;
540 		info.si_addr = (void __user *) location;
541 		do_trap(interruption_code, signal,
542 			"illegal operation", regs, &info);
543 	}
544 }
545 
546 
547 #ifdef CONFIG_MATHEMU
548 asmlinkage void
549 specification_exception(struct pt_regs * regs, long interruption_code)
550 {
551         __u8 opcode[6];
552 	__u16 __user *location = NULL;
553 	int signal = 0;
554 
555 	location = (__u16 __user *) get_check_address(regs);
556 
557 	/*
558 	 * We got all needed information from the lowcore and can
559 	 * now safely switch on interrupts.
560 	 */
561         if (regs->psw.mask & PSW_MASK_PSTATE)
562 		local_irq_enable();
563 
564         if (regs->psw.mask & PSW_MASK_PSTATE) {
565 		get_user(*((__u16 *) opcode), location);
566 		switch (opcode[0]) {
567 		case 0x28: /* LDR Rx,Ry   */
568 			signal = math_emu_ldr(opcode);
569 			break;
570 		case 0x38: /* LER Rx,Ry   */
571 			signal = math_emu_ler(opcode);
572 			break;
573 		case 0x60: /* STD R,D(X,B) */
574 			get_user(*((__u16 *) (opcode+2)), location+1);
575 			signal = math_emu_std(opcode, regs);
576 			break;
577 		case 0x68: /* LD R,D(X,B) */
578 			get_user(*((__u16 *) (opcode+2)), location+1);
579 			signal = math_emu_ld(opcode, regs);
580 			break;
581 		case 0x70: /* STE R,D(X,B) */
582 			get_user(*((__u16 *) (opcode+2)), location+1);
583 			signal = math_emu_ste(opcode, regs);
584 			break;
585 		case 0x78: /* LE R,D(X,B) */
586 			get_user(*((__u16 *) (opcode+2)), location+1);
587 			signal = math_emu_le(opcode, regs);
588 			break;
589 		default:
590 			signal = SIGILL;
591 			break;
592                 }
593         } else
594 		signal = SIGILL;
595 
596         if (signal == SIGFPE)
597 		do_fp_trap(regs, location,
598                            current->thread.fp_regs.fpc, interruption_code);
599         else if (signal) {
600 		siginfo_t info;
601 		info.si_signo = signal;
602 		info.si_errno = 0;
603 		info.si_code = ILL_ILLOPN;
604 		info.si_addr = location;
605 		do_trap(interruption_code, signal,
606 			"specification exception", regs, &info);
607 	}
608 }
609 #else
610 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
611 	      ILL_ILLOPN, get_check_address(regs));
612 #endif
613 
614 static void data_exception(struct pt_regs * regs, long interruption_code)
615 {
616 	__u16 __user *location;
617 	int signal = 0;
618 
619 	location = get_check_address(regs);
620 
621 	/*
622 	 * We got all needed information from the lowcore and can
623 	 * now safely switch on interrupts.
624 	 */
625 	if (regs->psw.mask & PSW_MASK_PSTATE)
626 		local_irq_enable();
627 
628 	if (MACHINE_HAS_IEEE)
629 		asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
630 
631 #ifdef CONFIG_MATHEMU
632         else if (regs->psw.mask & PSW_MASK_PSTATE) {
633         	__u8 opcode[6];
634 		get_user(*((__u16 *) opcode), location);
635 		switch (opcode[0]) {
636 		case 0x28: /* LDR Rx,Ry   */
637 			signal = math_emu_ldr(opcode);
638 			break;
639 		case 0x38: /* LER Rx,Ry   */
640 			signal = math_emu_ler(opcode);
641 			break;
642 		case 0x60: /* STD R,D(X,B) */
643 			get_user(*((__u16 *) (opcode+2)), location+1);
644 			signal = math_emu_std(opcode, regs);
645 			break;
646 		case 0x68: /* LD R,D(X,B) */
647 			get_user(*((__u16 *) (opcode+2)), location+1);
648 			signal = math_emu_ld(opcode, regs);
649 			break;
650 		case 0x70: /* STE R,D(X,B) */
651 			get_user(*((__u16 *) (opcode+2)), location+1);
652 			signal = math_emu_ste(opcode, regs);
653 			break;
654 		case 0x78: /* LE R,D(X,B) */
655 			get_user(*((__u16 *) (opcode+2)), location+1);
656 			signal = math_emu_le(opcode, regs);
657 			break;
658 		case 0xb3:
659 			get_user(*((__u16 *) (opcode+2)), location+1);
660 			signal = math_emu_b3(opcode, regs);
661 			break;
662                 case 0xed:
663 			get_user(*((__u32 *) (opcode+2)),
664 				 (__u32 __user *)(location+1));
665 			signal = math_emu_ed(opcode, regs);
666 			break;
667 	        case 0xb2:
668 			if (opcode[1] == 0x99) {
669 				get_user(*((__u16 *) (opcode+2)), location+1);
670 				signal = math_emu_srnm(opcode, regs);
671 			} else if (opcode[1] == 0x9c) {
672 				get_user(*((__u16 *) (opcode+2)), location+1);
673 				signal = math_emu_stfpc(opcode, regs);
674 			} else if (opcode[1] == 0x9d) {
675 				get_user(*((__u16 *) (opcode+2)), location+1);
676 				signal = math_emu_lfpc(opcode, regs);
677 			} else
678 				signal = SIGILL;
679 			break;
680 		default:
681 			signal = SIGILL;
682 			break;
683                 }
684         }
685 #endif
686 	if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
687 		signal = SIGFPE;
688 	else
689 		signal = SIGILL;
690         if (signal == SIGFPE)
691 		do_fp_trap(regs, location,
692                            current->thread.fp_regs.fpc, interruption_code);
693         else if (signal) {
694 		siginfo_t info;
695 		info.si_signo = signal;
696 		info.si_errno = 0;
697 		info.si_code = ILL_ILLOPN;
698 		info.si_addr = location;
699 		do_trap(interruption_code, signal,
700 			"data exception", regs, &info);
701 	}
702 }
703 
704 static void space_switch_exception(struct pt_regs * regs, long int_code)
705 {
706         siginfo_t info;
707 
708 	/* Set user psw back to home space mode. */
709 	if (regs->psw.mask & PSW_MASK_PSTATE)
710 		regs->psw.mask |= PSW_ASC_HOME;
711 	/* Send SIGILL. */
712         info.si_signo = SIGILL;
713         info.si_errno = 0;
714         info.si_code = ILL_PRVOPC;
715         info.si_addr = get_check_address(regs);
716         do_trap(int_code, SIGILL, "space switch event", regs, &info);
717 }
718 
719 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
720 {
721 	bust_spinlocks(1);
722 	printk("Kernel stack overflow.\n");
723 	show_regs(regs);
724 	bust_spinlocks(0);
725 	panic("Corrupt kernel stack, can't continue.");
726 }
727 
728 /* init is done in lowcore.S and head.S */
729 
730 void __init trap_init(void)
731 {
732         int i;
733 
734         for (i = 0; i < 128; i++)
735           pgm_check_table[i] = &default_trap_handler;
736         pgm_check_table[1] = &illegal_op;
737         pgm_check_table[2] = &privileged_op;
738         pgm_check_table[3] = &execute_exception;
739         pgm_check_table[4] = &do_protection_exception;
740         pgm_check_table[5] = &addressing_exception;
741         pgm_check_table[6] = &specification_exception;
742         pgm_check_table[7] = &data_exception;
743         pgm_check_table[8] = &overflow_exception;
744         pgm_check_table[9] = &divide_exception;
745         pgm_check_table[0x0A] = &overflow_exception;
746         pgm_check_table[0x0B] = &divide_exception;
747         pgm_check_table[0x0C] = &hfp_overflow_exception;
748         pgm_check_table[0x0D] = &hfp_underflow_exception;
749         pgm_check_table[0x0E] = &hfp_significance_exception;
750         pgm_check_table[0x0F] = &hfp_divide_exception;
751         pgm_check_table[0x10] = &do_dat_exception;
752         pgm_check_table[0x11] = &do_dat_exception;
753         pgm_check_table[0x12] = &translation_exception;
754         pgm_check_table[0x13] = &special_op_exception;
755 #ifdef CONFIG_64BIT
756 	pgm_check_table[0x38] = &do_asce_exception;
757 	pgm_check_table[0x39] = &do_dat_exception;
758 	pgm_check_table[0x3A] = &do_dat_exception;
759         pgm_check_table[0x3B] = &do_dat_exception;
760 #endif /* CONFIG_64BIT */
761         pgm_check_table[0x15] = &operand_exception;
762         pgm_check_table[0x1C] = &space_switch_exception;
763         pgm_check_table[0x1D] = &hfp_sqrt_exception;
764 	pfault_irq_init();
765 }
766