xref: /openbmc/linux/arch/s390/kernel/traps.c (revision a1e58bbd)
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 
46 /* Called from entry.S only */
47 extern void handle_per_exception(struct pt_regs *regs);
48 
49 typedef void pgm_check_handler_t(struct pt_regs *, long);
50 pgm_check_handler_t *pgm_check_table[128];
51 
52 #ifdef CONFIG_SYSCTL
53 #ifdef CONFIG_PROCESS_DEBUG
54 int sysctl_userprocess_debug = 1;
55 #else
56 int sysctl_userprocess_debug = 0;
57 #endif
58 #endif
59 
60 extern pgm_check_handler_t do_protection_exception;
61 extern pgm_check_handler_t do_dat_exception;
62 extern pgm_check_handler_t do_monitor_call;
63 extern pgm_check_handler_t do_asce_exception;
64 
65 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
66 
67 #ifndef CONFIG_64BIT
68 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
69 static int kstack_depth_to_print = 12;
70 #else /* CONFIG_64BIT */
71 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
72 static int kstack_depth_to_print = 20;
73 #endif /* CONFIG_64BIT */
74 
75 /*
76  * For show_trace we have tree different stack to consider:
77  *   - the panic stack which is used if the kernel stack has overflown
78  *   - the asynchronous interrupt stack (cpu related)
79  *   - the synchronous kernel stack (process related)
80  * The stack trace can start at any of the three stack and can potentially
81  * touch all of them. The order is: panic stack, async stack, sync stack.
82  */
83 static unsigned long
84 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
85 {
86 	struct stack_frame *sf;
87 	struct pt_regs *regs;
88 
89 	while (1) {
90 		sp = sp & PSW_ADDR_INSN;
91 		if (sp < low || sp > high - sizeof(*sf))
92 			return sp;
93 		sf = (struct stack_frame *) sp;
94 		printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
95 		print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
96 		/* Follow the backchain. */
97 		while (1) {
98 			low = sp;
99 			sp = sf->back_chain & PSW_ADDR_INSN;
100 			if (!sp)
101 				break;
102 			if (sp <= low || sp > high - sizeof(*sf))
103 				return sp;
104 			sf = (struct stack_frame *) sp;
105 			printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
106 			print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
107 		}
108 		/* Zero backchain detected, check for interrupt frame. */
109 		sp = (unsigned long) (sf + 1);
110 		if (sp <= low || sp > high - sizeof(*regs))
111 			return sp;
112 		regs = (struct pt_regs *) sp;
113 		printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
114 		print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
115 		low = sp;
116 		sp = regs->gprs[15];
117 	}
118 }
119 
120 void show_trace(struct task_struct *task, unsigned long *stack)
121 {
122 	register unsigned long __r15 asm ("15");
123 	unsigned long sp;
124 
125 	sp = (unsigned long) stack;
126 	if (!sp)
127 		sp = task ? task->thread.ksp : __r15;
128 	printk("Call Trace:\n");
129 #ifdef CONFIG_CHECK_STACK
130 	sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
131 			  S390_lowcore.panic_stack);
132 #endif
133 	sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
134 			  S390_lowcore.async_stack);
135 	if (task)
136 		__show_trace(sp, (unsigned long) task_stack_page(task),
137 			     (unsigned long) task_stack_page(task) + THREAD_SIZE);
138 	else
139 		__show_trace(sp, S390_lowcore.thread_info,
140 			     S390_lowcore.thread_info + THREAD_SIZE);
141 	printk("\n");
142 	if (!task)
143 		task = current;
144 	debug_show_held_locks(task);
145 }
146 
147 void show_stack(struct task_struct *task, unsigned long *sp)
148 {
149 	register unsigned long * __r15 asm ("15");
150 	unsigned long *stack;
151 	int i;
152 
153 	if (!sp)
154 		stack = task ? (unsigned long *) task->thread.ksp : __r15;
155 	else
156 		stack = sp;
157 
158 	for (i = 0; i < kstack_depth_to_print; i++) {
159 		if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
160 			break;
161 		if (i && ((i * sizeof (long) % 32) == 0))
162 			printk("\n       ");
163 		printk("%p ", (void *)*stack++);
164 	}
165 	printk("\n");
166 	show_trace(task, sp);
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 /* This is called from fs/proc/array.c */
223 void task_show_regs(struct seq_file *m, struct task_struct *task)
224 {
225 	struct pt_regs *regs;
226 
227 	regs = task_pt_regs(task);
228 	seq_printf(m, "task: %p, ksp: %p\n",
229 		       task, (void *)task->thread.ksp);
230 	seq_printf(m, "User PSW : %p %p\n",
231 		       (void *) regs->psw.mask, (void *)regs->psw.addr);
232 
233 	seq_printf(m, "User GPRS: " FOURLONG,
234 			  regs->gprs[0], regs->gprs[1],
235 			  regs->gprs[2], regs->gprs[3]);
236 	seq_printf(m, "           " FOURLONG,
237 			  regs->gprs[4], regs->gprs[5],
238 			  regs->gprs[6], regs->gprs[7]);
239 	seq_printf(m, "           " FOURLONG,
240 			  regs->gprs[8], regs->gprs[9],
241 			  regs->gprs[10], regs->gprs[11]);
242 	seq_printf(m, "           " FOURLONG,
243 			  regs->gprs[12], regs->gprs[13],
244 			  regs->gprs[14], regs->gprs[15]);
245 	seq_printf(m, "User ACRS: %08x %08x %08x %08x\n",
246 			  task->thread.acrs[0], task->thread.acrs[1],
247 			  task->thread.acrs[2], task->thread.acrs[3]);
248 	seq_printf(m, "           %08x %08x %08x %08x\n",
249 			  task->thread.acrs[4], task->thread.acrs[5],
250 			  task->thread.acrs[6], task->thread.acrs[7]);
251 	seq_printf(m, "           %08x %08x %08x %08x\n",
252 			  task->thread.acrs[8], task->thread.acrs[9],
253 			  task->thread.acrs[10], task->thread.acrs[11]);
254 	seq_printf(m, "           %08x %08x %08x %08x\n",
255 			  task->thread.acrs[12], task->thread.acrs[13],
256 			  task->thread.acrs[14], task->thread.acrs[15]);
257 }
258 
259 static DEFINE_SPINLOCK(die_lock);
260 
261 void die(const char * str, struct pt_regs * regs, long err)
262 {
263 	static int die_counter;
264 
265 	oops_enter();
266 	debug_stop_all();
267 	console_verbose();
268 	spin_lock_irq(&die_lock);
269 	bust_spinlocks(1);
270 	printk("%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
271 #ifdef CONFIG_PREEMPT
272 	printk("PREEMPT ");
273 #endif
274 #ifdef CONFIG_SMP
275 	printk("SMP ");
276 #endif
277 #ifdef CONFIG_DEBUG_PAGEALLOC
278 	printk("DEBUG_PAGEALLOC");
279 #endif
280 	printk("\n");
281 	notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
282 	show_regs(regs);
283 	bust_spinlocks(0);
284 	add_taint(TAINT_DIE);
285 	spin_unlock_irq(&die_lock);
286 	if (in_interrupt())
287 		panic("Fatal exception in interrupt");
288 	if (panic_on_oops)
289 		panic("Fatal exception: panic_on_oops");
290 	oops_exit();
291 	do_exit(SIGSEGV);
292 }
293 
294 static void inline
295 report_user_fault(long interruption_code, struct pt_regs *regs)
296 {
297 #if defined(CONFIG_SYSCTL)
298 	if (!sysctl_userprocess_debug)
299 		return;
300 #endif
301 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
302 	printk("User process fault: interruption code 0x%lX\n",
303 	       interruption_code);
304 	show_regs(regs);
305 #endif
306 }
307 
308 int is_valid_bugaddr(unsigned long addr)
309 {
310 	return 1;
311 }
312 
313 static void __kprobes inline do_trap(long interruption_code, int signr,
314 					char *str, struct pt_regs *regs,
315 					siginfo_t *info)
316 {
317 	/*
318 	 * We got all needed information from the lowcore and can
319 	 * now safely switch on interrupts.
320 	 */
321         if (regs->psw.mask & PSW_MASK_PSTATE)
322 		local_irq_enable();
323 
324 	if (notify_die(DIE_TRAP, str, regs, interruption_code,
325 				interruption_code, signr) == NOTIFY_STOP)
326 		return;
327 
328         if (regs->psw.mask & PSW_MASK_PSTATE) {
329                 struct task_struct *tsk = current;
330 
331                 tsk->thread.trap_no = interruption_code & 0xffff;
332 		force_sig_info(signr, info, tsk);
333 		report_user_fault(interruption_code, regs);
334         } else {
335                 const struct exception_table_entry *fixup;
336                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
337                 if (fixup)
338                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
339 		else {
340 			enum bug_trap_type btt;
341 
342 			btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
343 			if (btt == BUG_TRAP_TYPE_WARN)
344 				return;
345 			die(str, regs, interruption_code);
346 		}
347         }
348 }
349 
350 static inline void __user *get_check_address(struct pt_regs *regs)
351 {
352 	return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
353 }
354 
355 void __kprobes do_single_step(struct pt_regs *regs)
356 {
357 	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
358 					SIGTRAP) == NOTIFY_STOP){
359 		return;
360 	}
361 	if ((current->ptrace & PT_PTRACED) != 0)
362 		force_sig(SIGTRAP, current);
363 }
364 
365 static void default_trap_handler(struct pt_regs * regs, long interruption_code)
366 {
367         if (regs->psw.mask & PSW_MASK_PSTATE) {
368 		local_irq_enable();
369 		do_exit(SIGSEGV);
370 		report_user_fault(interruption_code, regs);
371 	} else
372 		die("Unknown program exception", regs, interruption_code);
373 }
374 
375 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
376 static void name(struct pt_regs * regs, long interruption_code) \
377 { \
378         siginfo_t info; \
379         info.si_signo = signr; \
380         info.si_errno = 0; \
381         info.si_code = sicode; \
382 	info.si_addr = siaddr; \
383         do_trap(interruption_code, signr, str, regs, &info); \
384 }
385 
386 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
387 	      ILL_ILLADR, get_check_address(regs))
388 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
389 	      ILL_ILLOPN, get_check_address(regs))
390 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
391 	      FPE_INTDIV, get_check_address(regs))
392 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
393 	      FPE_INTOVF, get_check_address(regs))
394 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
395 	      FPE_FLTOVF, get_check_address(regs))
396 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
397 	      FPE_FLTUND, get_check_address(regs))
398 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
399 	      FPE_FLTRES, get_check_address(regs))
400 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
401 	      FPE_FLTDIV, get_check_address(regs))
402 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
403 	      FPE_FLTINV, get_check_address(regs))
404 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
405 	      ILL_ILLOPN, get_check_address(regs))
406 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
407 	      ILL_PRVOPC, get_check_address(regs))
408 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
409 	      ILL_ILLOPN, get_check_address(regs))
410 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
411 	      ILL_ILLOPN, get_check_address(regs))
412 
413 static inline void
414 do_fp_trap(struct pt_regs *regs, void __user *location,
415            int fpc, long interruption_code)
416 {
417 	siginfo_t si;
418 
419 	si.si_signo = SIGFPE;
420 	si.si_errno = 0;
421 	si.si_addr = location;
422 	si.si_code = 0;
423 	/* FPC[2] is Data Exception Code */
424 	if ((fpc & 0x00000300) == 0) {
425 		/* bits 6 and 7 of DXC are 0 iff IEEE exception */
426 		if (fpc & 0x8000) /* invalid fp operation */
427 			si.si_code = FPE_FLTINV;
428 		else if (fpc & 0x4000) /* div by 0 */
429 			si.si_code = FPE_FLTDIV;
430 		else if (fpc & 0x2000) /* overflow */
431 			si.si_code = FPE_FLTOVF;
432 		else if (fpc & 0x1000) /* underflow */
433 			si.si_code = FPE_FLTUND;
434 		else if (fpc & 0x0800) /* inexact */
435 			si.si_code = FPE_FLTRES;
436 	}
437 	current->thread.ieee_instruction_pointer = (addr_t) location;
438 	do_trap(interruption_code, SIGFPE,
439 		"floating point exception", regs, &si);
440 }
441 
442 static void illegal_op(struct pt_regs * regs, long interruption_code)
443 {
444 	siginfo_t info;
445         __u8 opcode[6];
446 	__u16 __user *location;
447 	int signal = 0;
448 
449 	location = get_check_address(regs);
450 
451 	/*
452 	 * We got all needed information from the lowcore and can
453 	 * now safely switch on interrupts.
454 	 */
455 	if (regs->psw.mask & PSW_MASK_PSTATE)
456 		local_irq_enable();
457 
458 	if (regs->psw.mask & PSW_MASK_PSTATE) {
459 		if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
460 			return;
461 		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
462 			if (current->ptrace & PT_PTRACED)
463 				force_sig(SIGTRAP, current);
464 			else
465 				signal = SIGILL;
466 #ifdef CONFIG_MATHEMU
467 		} else if (opcode[0] == 0xb3) {
468 			if (get_user(*((__u16 *) (opcode+2)), location+1))
469 				return;
470 			signal = math_emu_b3(opcode, regs);
471                 } else if (opcode[0] == 0xed) {
472 			if (get_user(*((__u32 *) (opcode+2)),
473 				     (__u32 __user *)(location+1)))
474 				return;
475 			signal = math_emu_ed(opcode, regs);
476 		} else if (*((__u16 *) opcode) == 0xb299) {
477 			if (get_user(*((__u16 *) (opcode+2)), location+1))
478 				return;
479 			signal = math_emu_srnm(opcode, regs);
480 		} else if (*((__u16 *) opcode) == 0xb29c) {
481 			if (get_user(*((__u16 *) (opcode+2)), location+1))
482 				return;
483 			signal = math_emu_stfpc(opcode, regs);
484 		} else if (*((__u16 *) opcode) == 0xb29d) {
485 			if (get_user(*((__u16 *) (opcode+2)), location+1))
486 				return;
487 			signal = math_emu_lfpc(opcode, regs);
488 #endif
489 		} else
490 			signal = SIGILL;
491 	} else {
492 		/*
493 		 * If we get an illegal op in kernel mode, send it through the
494 		 * kprobes notifier. If kprobes doesn't pick it up, SIGILL
495 		 */
496 		if (notify_die(DIE_BPT, "bpt", regs, interruption_code,
497 			       3, SIGTRAP) != NOTIFY_STOP)
498 			signal = SIGILL;
499 	}
500 
501 #ifdef CONFIG_MATHEMU
502         if (signal == SIGFPE)
503 		do_fp_trap(regs, location,
504                            current->thread.fp_regs.fpc, interruption_code);
505         else if (signal == SIGSEGV) {
506 		info.si_signo = signal;
507 		info.si_errno = 0;
508 		info.si_code = SEGV_MAPERR;
509 		info.si_addr = (void __user *) location;
510 		do_trap(interruption_code, signal,
511 			"user address fault", regs, &info);
512 	} else
513 #endif
514         if (signal) {
515 		info.si_signo = signal;
516 		info.si_errno = 0;
517 		info.si_code = ILL_ILLOPC;
518 		info.si_addr = (void __user *) location;
519 		do_trap(interruption_code, signal,
520 			"illegal operation", regs, &info);
521 	}
522 }
523 
524 
525 #ifdef CONFIG_MATHEMU
526 asmlinkage void
527 specification_exception(struct pt_regs * regs, long interruption_code)
528 {
529         __u8 opcode[6];
530 	__u16 __user *location = NULL;
531 	int signal = 0;
532 
533 	location = (__u16 __user *) get_check_address(regs);
534 
535 	/*
536 	 * We got all needed information from the lowcore and can
537 	 * now safely switch on interrupts.
538 	 */
539         if (regs->psw.mask & PSW_MASK_PSTATE)
540 		local_irq_enable();
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, interruption_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(interruption_code, signal,
584 			"specification exception", regs, &info);
585 	}
586 }
587 #else
588 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
589 	      ILL_ILLOPN, get_check_address(regs));
590 #endif
591 
592 static void data_exception(struct pt_regs * regs, long interruption_code)
593 {
594 	__u16 __user *location;
595 	int signal = 0;
596 
597 	location = get_check_address(regs);
598 
599 	/*
600 	 * We got all needed information from the lowcore and can
601 	 * now safely switch on interrupts.
602 	 */
603 	if (regs->psw.mask & PSW_MASK_PSTATE)
604 		local_irq_enable();
605 
606 	if (MACHINE_HAS_IEEE)
607 		asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
608 
609 #ifdef CONFIG_MATHEMU
610         else if (regs->psw.mask & PSW_MASK_PSTATE) {
611         	__u8 opcode[6];
612 		get_user(*((__u16 *) opcode), location);
613 		switch (opcode[0]) {
614 		case 0x28: /* LDR Rx,Ry   */
615 			signal = math_emu_ldr(opcode);
616 			break;
617 		case 0x38: /* LER Rx,Ry   */
618 			signal = math_emu_ler(opcode);
619 			break;
620 		case 0x60: /* STD R,D(X,B) */
621 			get_user(*((__u16 *) (opcode+2)), location+1);
622 			signal = math_emu_std(opcode, regs);
623 			break;
624 		case 0x68: /* LD R,D(X,B) */
625 			get_user(*((__u16 *) (opcode+2)), location+1);
626 			signal = math_emu_ld(opcode, regs);
627 			break;
628 		case 0x70: /* STE R,D(X,B) */
629 			get_user(*((__u16 *) (opcode+2)), location+1);
630 			signal = math_emu_ste(opcode, regs);
631 			break;
632 		case 0x78: /* LE R,D(X,B) */
633 			get_user(*((__u16 *) (opcode+2)), location+1);
634 			signal = math_emu_le(opcode, regs);
635 			break;
636 		case 0xb3:
637 			get_user(*((__u16 *) (opcode+2)), location+1);
638 			signal = math_emu_b3(opcode, regs);
639 			break;
640                 case 0xed:
641 			get_user(*((__u32 *) (opcode+2)),
642 				 (__u32 __user *)(location+1));
643 			signal = math_emu_ed(opcode, regs);
644 			break;
645 	        case 0xb2:
646 			if (opcode[1] == 0x99) {
647 				get_user(*((__u16 *) (opcode+2)), location+1);
648 				signal = math_emu_srnm(opcode, regs);
649 			} else if (opcode[1] == 0x9c) {
650 				get_user(*((__u16 *) (opcode+2)), location+1);
651 				signal = math_emu_stfpc(opcode, regs);
652 			} else if (opcode[1] == 0x9d) {
653 				get_user(*((__u16 *) (opcode+2)), location+1);
654 				signal = math_emu_lfpc(opcode, regs);
655 			} else
656 				signal = SIGILL;
657 			break;
658 		default:
659 			signal = SIGILL;
660 			break;
661                 }
662         }
663 #endif
664 	if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
665 		signal = SIGFPE;
666 	else
667 		signal = SIGILL;
668         if (signal == SIGFPE)
669 		do_fp_trap(regs, location,
670                            current->thread.fp_regs.fpc, interruption_code);
671         else if (signal) {
672 		siginfo_t info;
673 		info.si_signo = signal;
674 		info.si_errno = 0;
675 		info.si_code = ILL_ILLOPN;
676 		info.si_addr = location;
677 		do_trap(interruption_code, signal,
678 			"data exception", regs, &info);
679 	}
680 }
681 
682 static void space_switch_exception(struct pt_regs * regs, long int_code)
683 {
684         siginfo_t info;
685 
686 	/* Set user psw back to home space mode. */
687 	if (regs->psw.mask & PSW_MASK_PSTATE)
688 		regs->psw.mask |= PSW_ASC_HOME;
689 	/* Send SIGILL. */
690         info.si_signo = SIGILL;
691         info.si_errno = 0;
692         info.si_code = ILL_PRVOPC;
693         info.si_addr = get_check_address(regs);
694         do_trap(int_code, SIGILL, "space switch event", regs, &info);
695 }
696 
697 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
698 {
699 	bust_spinlocks(1);
700 	printk("Kernel stack overflow.\n");
701 	show_regs(regs);
702 	bust_spinlocks(0);
703 	panic("Corrupt kernel stack, can't continue.");
704 }
705 
706 /* init is done in lowcore.S and head.S */
707 
708 void __init trap_init(void)
709 {
710         int i;
711 
712         for (i = 0; i < 128; i++)
713           pgm_check_table[i] = &default_trap_handler;
714         pgm_check_table[1] = &illegal_op;
715         pgm_check_table[2] = &privileged_op;
716         pgm_check_table[3] = &execute_exception;
717         pgm_check_table[4] = &do_protection_exception;
718         pgm_check_table[5] = &addressing_exception;
719         pgm_check_table[6] = &specification_exception;
720         pgm_check_table[7] = &data_exception;
721         pgm_check_table[8] = &overflow_exception;
722         pgm_check_table[9] = &divide_exception;
723         pgm_check_table[0x0A] = &overflow_exception;
724         pgm_check_table[0x0B] = &divide_exception;
725         pgm_check_table[0x0C] = &hfp_overflow_exception;
726         pgm_check_table[0x0D] = &hfp_underflow_exception;
727         pgm_check_table[0x0E] = &hfp_significance_exception;
728         pgm_check_table[0x0F] = &hfp_divide_exception;
729         pgm_check_table[0x10] = &do_dat_exception;
730         pgm_check_table[0x11] = &do_dat_exception;
731         pgm_check_table[0x12] = &translation_exception;
732         pgm_check_table[0x13] = &special_op_exception;
733 #ifdef CONFIG_64BIT
734 	pgm_check_table[0x38] = &do_asce_exception;
735 	pgm_check_table[0x39] = &do_dat_exception;
736 	pgm_check_table[0x3A] = &do_dat_exception;
737         pgm_check_table[0x3B] = &do_dat_exception;
738 #endif /* CONFIG_64BIT */
739         pgm_check_table[0x15] = &operand_exception;
740         pgm_check_table[0x1C] = &space_switch_exception;
741         pgm_check_table[0x1D] = &hfp_sqrt_exception;
742 	pgm_check_table[0x40] = &do_monitor_call;
743 	pfault_irq_init();
744 }
745