xref: /openbmc/linux/arch/s390/kernel/traps.c (revision 643d1f7f)
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/delay.h>
28 #include <linux/module.h>
29 #include <linux/kdebug.h>
30 #include <linux/kallsyms.h>
31 #include <linux/reboot.h>
32 #include <linux/kprobes.h>
33 #include <linux/bug.h>
34 #include <linux/utsname.h>
35 #include <asm/system.h>
36 #include <asm/uaccess.h>
37 #include <asm/io.h>
38 #include <asm/atomic.h>
39 #include <asm/mathemu.h>
40 #include <asm/cpcmd.h>
41 #include <asm/s390_ext.h>
42 #include <asm/lowcore.h>
43 #include <asm/debug.h>
44 
45 /* Called from entry.S only */
46 extern void handle_per_exception(struct pt_regs *regs);
47 
48 typedef void pgm_check_handler_t(struct pt_regs *, long);
49 pgm_check_handler_t *pgm_check_table[128];
50 
51 #ifdef CONFIG_SYSCTL
52 #ifdef CONFIG_PROCESS_DEBUG
53 int sysctl_userprocess_debug = 1;
54 #else
55 int sysctl_userprocess_debug = 0;
56 #endif
57 #endif
58 
59 extern pgm_check_handler_t do_protection_exception;
60 extern pgm_check_handler_t do_dat_exception;
61 extern pgm_check_handler_t do_monitor_call;
62 
63 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
64 
65 #ifndef CONFIG_64BIT
66 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
67 static int kstack_depth_to_print = 12;
68 #else /* CONFIG_64BIT */
69 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
70 static int kstack_depth_to_print = 20;
71 #endif /* CONFIG_64BIT */
72 
73 /*
74  * For show_trace we have tree different stack to consider:
75  *   - the panic stack which is used if the kernel stack has overflown
76  *   - the asynchronous interrupt stack (cpu related)
77  *   - the synchronous kernel stack (process related)
78  * The stack trace can start at any of the three stack and can potentially
79  * touch all of them. The order is: panic stack, async stack, sync stack.
80  */
81 static unsigned long
82 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
83 {
84 	struct stack_frame *sf;
85 	struct pt_regs *regs;
86 
87 	while (1) {
88 		sp = sp & PSW_ADDR_INSN;
89 		if (sp < low || sp > high - sizeof(*sf))
90 			return sp;
91 		sf = (struct stack_frame *) sp;
92 		printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
93 		print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
94 		/* Follow the backchain. */
95 		while (1) {
96 			low = sp;
97 			sp = sf->back_chain & PSW_ADDR_INSN;
98 			if (!sp)
99 				break;
100 			if (sp <= low || sp > high - sizeof(*sf))
101 				return sp;
102 			sf = (struct stack_frame *) sp;
103 			printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
104 			print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
105 		}
106 		/* Zero backchain detected, check for interrupt frame. */
107 		sp = (unsigned long) (sf + 1);
108 		if (sp <= low || sp > high - sizeof(*regs))
109 			return sp;
110 		regs = (struct pt_regs *) sp;
111 		printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
112 		print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
113 		low = sp;
114 		sp = regs->gprs[15];
115 	}
116 }
117 
118 void show_trace(struct task_struct *task, unsigned long *stack)
119 {
120 	register unsigned long __r15 asm ("15");
121 	unsigned long sp;
122 
123 	sp = (unsigned long) stack;
124 	if (!sp)
125 		sp = task ? task->thread.ksp : __r15;
126 	printk("Call Trace:\n");
127 #ifdef CONFIG_CHECK_STACK
128 	sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
129 			  S390_lowcore.panic_stack);
130 #endif
131 	sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
132 			  S390_lowcore.async_stack);
133 	if (task)
134 		__show_trace(sp, (unsigned long) task_stack_page(task),
135 			     (unsigned long) task_stack_page(task) + THREAD_SIZE);
136 	else
137 		__show_trace(sp, S390_lowcore.thread_info,
138 			     S390_lowcore.thread_info + THREAD_SIZE);
139 	printk("\n");
140 	if (!task)
141 		task = current;
142 	debug_show_held_locks(task);
143 }
144 
145 void show_stack(struct task_struct *task, unsigned long *sp)
146 {
147 	register unsigned long * __r15 asm ("15");
148 	unsigned long *stack;
149 	int i;
150 
151 	if (!sp)
152 		stack = task ? (unsigned long *) task->thread.ksp : __r15;
153 	else
154 		stack = sp;
155 
156 	for (i = 0; i < kstack_depth_to_print; i++) {
157 		if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
158 			break;
159 		if (i && ((i * sizeof (long) % 32) == 0))
160 			printk("\n       ");
161 		printk("%p ", (void *)*stack++);
162 	}
163 	printk("\n");
164 	show_trace(task, sp);
165 }
166 
167 /*
168  * The architecture-independent dump_stack generator
169  */
170 void dump_stack(void)
171 {
172 	printk("CPU: %d %s %s %.*s\n",
173 	       task_thread_info(current)->cpu, print_tainted(),
174 	       init_utsname()->release,
175 	       (int)strcspn(init_utsname()->version, " "),
176 	       init_utsname()->version);
177 	printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
178 	       current->comm, current->pid, current,
179 	       (void *) current->thread.ksp);
180 	show_stack(NULL, NULL);
181 }
182 EXPORT_SYMBOL(dump_stack);
183 
184 static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
185 {
186 	return (regs->psw.mask & bits) / ((~bits + 1) & bits);
187 }
188 
189 void show_registers(struct pt_regs *regs)
190 {
191 	char *mode;
192 
193 	mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
194 	printk("%s PSW : %p %p",
195 	       mode, (void *) regs->psw.mask,
196 	       (void *) regs->psw.addr);
197 	print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
198 	printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
199 	       "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
200 	       mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
201 	       mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
202 	       mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
203 	       mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
204 	       mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
205 #ifdef CONFIG_64BIT
206 	printk(" EA:%x", mask_bits(regs, PSW_BASE_BITS));
207 #endif
208 	printk("\n%s GPRS: " FOURLONG, mode,
209 	       regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
210 	printk("           " FOURLONG,
211 	       regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
212 	printk("           " FOURLONG,
213 	       regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
214 	printk("           " FOURLONG,
215 	       regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
216 
217 	show_code(regs);
218 }
219 
220 /* This is called from fs/proc/array.c */
221 char *task_show_regs(struct task_struct *task, char *buffer)
222 {
223 	struct pt_regs *regs;
224 
225 	regs = task_pt_regs(task);
226 	buffer += sprintf(buffer, "task: %p, ksp: %p\n",
227 		       task, (void *)task->thread.ksp);
228 	buffer += sprintf(buffer, "User PSW : %p %p\n",
229 		       (void *) regs->psw.mask, (void *)regs->psw.addr);
230 
231 	buffer += sprintf(buffer, "User GPRS: " FOURLONG,
232 			  regs->gprs[0], regs->gprs[1],
233 			  regs->gprs[2], regs->gprs[3]);
234 	buffer += sprintf(buffer, "           " FOURLONG,
235 			  regs->gprs[4], regs->gprs[5],
236 			  regs->gprs[6], regs->gprs[7]);
237 	buffer += sprintf(buffer, "           " FOURLONG,
238 			  regs->gprs[8], regs->gprs[9],
239 			  regs->gprs[10], regs->gprs[11]);
240 	buffer += sprintf(buffer, "           " FOURLONG,
241 			  regs->gprs[12], regs->gprs[13],
242 			  regs->gprs[14], regs->gprs[15]);
243 	buffer += sprintf(buffer, "User ACRS: %08x %08x %08x %08x\n",
244 			  task->thread.acrs[0], task->thread.acrs[1],
245 			  task->thread.acrs[2], task->thread.acrs[3]);
246 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
247 			  task->thread.acrs[4], task->thread.acrs[5],
248 			  task->thread.acrs[6], task->thread.acrs[7]);
249 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
250 			  task->thread.acrs[8], task->thread.acrs[9],
251 			  task->thread.acrs[10], task->thread.acrs[11]);
252 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
253 			  task->thread.acrs[12], task->thread.acrs[13],
254 			  task->thread.acrs[14], task->thread.acrs[15]);
255 	return buffer;
256 }
257 
258 static DEFINE_SPINLOCK(die_lock);
259 
260 void die(const char * str, struct pt_regs * regs, long err)
261 {
262 	static int die_counter;
263 
264 	oops_enter();
265 	debug_stop_all();
266 	console_verbose();
267 	spin_lock_irq(&die_lock);
268 	bust_spinlocks(1);
269 	printk("%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
270 #ifdef CONFIG_PREEMPT
271 	printk("PREEMPT ");
272 #endif
273 #ifdef CONFIG_SMP
274 	printk("SMP");
275 #endif
276 	printk("\n");
277 	notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
278 	show_regs(regs);
279 	bust_spinlocks(0);
280 	add_taint(TAINT_DIE);
281 	spin_unlock_irq(&die_lock);
282 	if (in_interrupt())
283 		panic("Fatal exception in interrupt");
284 	if (panic_on_oops)
285 		panic("Fatal exception: panic_on_oops");
286 	oops_exit();
287 	do_exit(SIGSEGV);
288 }
289 
290 static void inline
291 report_user_fault(long interruption_code, struct pt_regs *regs)
292 {
293 #if defined(CONFIG_SYSCTL)
294 	if (!sysctl_userprocess_debug)
295 		return;
296 #endif
297 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
298 	printk("User process fault: interruption code 0x%lX\n",
299 	       interruption_code);
300 	show_regs(regs);
301 #endif
302 }
303 
304 int is_valid_bugaddr(unsigned long addr)
305 {
306 	return 1;
307 }
308 
309 static void __kprobes inline do_trap(long interruption_code, int signr,
310 					char *str, struct pt_regs *regs,
311 					siginfo_t *info)
312 {
313 	/*
314 	 * We got all needed information from the lowcore and can
315 	 * now safely switch on interrupts.
316 	 */
317         if (regs->psw.mask & PSW_MASK_PSTATE)
318 		local_irq_enable();
319 
320 	if (notify_die(DIE_TRAP, str, regs, interruption_code,
321 				interruption_code, signr) == NOTIFY_STOP)
322 		return;
323 
324         if (regs->psw.mask & PSW_MASK_PSTATE) {
325                 struct task_struct *tsk = current;
326 
327                 tsk->thread.trap_no = interruption_code & 0xffff;
328 		force_sig_info(signr, info, tsk);
329 		report_user_fault(interruption_code, regs);
330         } else {
331                 const struct exception_table_entry *fixup;
332                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
333                 if (fixup)
334                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
335 		else {
336 			enum bug_trap_type btt;
337 
338 			btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
339 			if (btt == BUG_TRAP_TYPE_WARN)
340 				return;
341 			die(str, regs, interruption_code);
342 		}
343         }
344 }
345 
346 static inline void __user *get_check_address(struct pt_regs *regs)
347 {
348 	return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
349 }
350 
351 void __kprobes do_single_step(struct pt_regs *regs)
352 {
353 	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
354 					SIGTRAP) == NOTIFY_STOP){
355 		return;
356 	}
357 	if ((current->ptrace & PT_PTRACED) != 0)
358 		force_sig(SIGTRAP, current);
359 }
360 
361 static void default_trap_handler(struct pt_regs * regs, long interruption_code)
362 {
363         if (regs->psw.mask & PSW_MASK_PSTATE) {
364 		local_irq_enable();
365 		do_exit(SIGSEGV);
366 		report_user_fault(interruption_code, regs);
367 	} else
368 		die("Unknown program exception", regs, interruption_code);
369 }
370 
371 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
372 static void name(struct pt_regs * regs, long interruption_code) \
373 { \
374         siginfo_t info; \
375         info.si_signo = signr; \
376         info.si_errno = 0; \
377         info.si_code = sicode; \
378 	info.si_addr = siaddr; \
379         do_trap(interruption_code, signr, str, regs, &info); \
380 }
381 
382 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
383 	      ILL_ILLADR, get_check_address(regs))
384 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
385 	      ILL_ILLOPN, get_check_address(regs))
386 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
387 	      FPE_INTDIV, get_check_address(regs))
388 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
389 	      FPE_INTOVF, get_check_address(regs))
390 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
391 	      FPE_FLTOVF, get_check_address(regs))
392 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
393 	      FPE_FLTUND, get_check_address(regs))
394 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
395 	      FPE_FLTRES, get_check_address(regs))
396 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
397 	      FPE_FLTDIV, get_check_address(regs))
398 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
399 	      FPE_FLTINV, get_check_address(regs))
400 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
401 	      ILL_ILLOPN, get_check_address(regs))
402 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
403 	      ILL_PRVOPC, get_check_address(regs))
404 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
405 	      ILL_ILLOPN, get_check_address(regs))
406 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
407 	      ILL_ILLOPN, get_check_address(regs))
408 
409 static inline void
410 do_fp_trap(struct pt_regs *regs, void __user *location,
411            int fpc, long interruption_code)
412 {
413 	siginfo_t si;
414 
415 	si.si_signo = SIGFPE;
416 	si.si_errno = 0;
417 	si.si_addr = location;
418 	si.si_code = 0;
419 	/* FPC[2] is Data Exception Code */
420 	if ((fpc & 0x00000300) == 0) {
421 		/* bits 6 and 7 of DXC are 0 iff IEEE exception */
422 		if (fpc & 0x8000) /* invalid fp operation */
423 			si.si_code = FPE_FLTINV;
424 		else if (fpc & 0x4000) /* div by 0 */
425 			si.si_code = FPE_FLTDIV;
426 		else if (fpc & 0x2000) /* overflow */
427 			si.si_code = FPE_FLTOVF;
428 		else if (fpc & 0x1000) /* underflow */
429 			si.si_code = FPE_FLTUND;
430 		else if (fpc & 0x0800) /* inexact */
431 			si.si_code = FPE_FLTRES;
432 	}
433 	current->thread.ieee_instruction_pointer = (addr_t) location;
434 	do_trap(interruption_code, SIGFPE,
435 		"floating point exception", regs, &si);
436 }
437 
438 static void illegal_op(struct pt_regs * regs, long interruption_code)
439 {
440 	siginfo_t info;
441         __u8 opcode[6];
442 	__u16 __user *location;
443 	int signal = 0;
444 
445 	location = get_check_address(regs);
446 
447 	/*
448 	 * We got all needed information from the lowcore and can
449 	 * now safely switch on interrupts.
450 	 */
451 	if (regs->psw.mask & PSW_MASK_PSTATE)
452 		local_irq_enable();
453 
454 	if (regs->psw.mask & PSW_MASK_PSTATE) {
455 		if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
456 			return;
457 		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
458 			if (current->ptrace & PT_PTRACED)
459 				force_sig(SIGTRAP, current);
460 			else
461 				signal = SIGILL;
462 #ifdef CONFIG_MATHEMU
463 		} else if (opcode[0] == 0xb3) {
464 			if (get_user(*((__u16 *) (opcode+2)), location+1))
465 				return;
466 			signal = math_emu_b3(opcode, regs);
467                 } else if (opcode[0] == 0xed) {
468 			if (get_user(*((__u32 *) (opcode+2)),
469 				     (__u32 __user *)(location+1)))
470 				return;
471 			signal = math_emu_ed(opcode, regs);
472 		} else if (*((__u16 *) opcode) == 0xb299) {
473 			if (get_user(*((__u16 *) (opcode+2)), location+1))
474 				return;
475 			signal = math_emu_srnm(opcode, regs);
476 		} else if (*((__u16 *) opcode) == 0xb29c) {
477 			if (get_user(*((__u16 *) (opcode+2)), location+1))
478 				return;
479 			signal = math_emu_stfpc(opcode, regs);
480 		} else if (*((__u16 *) opcode) == 0xb29d) {
481 			if (get_user(*((__u16 *) (opcode+2)), location+1))
482 				return;
483 			signal = math_emu_lfpc(opcode, regs);
484 #endif
485 		} else
486 			signal = SIGILL;
487 	} else {
488 		/*
489 		 * If we get an illegal op in kernel mode, send it through the
490 		 * kprobes notifier. If kprobes doesn't pick it up, SIGILL
491 		 */
492 		if (notify_die(DIE_BPT, "bpt", regs, interruption_code,
493 			       3, SIGTRAP) != NOTIFY_STOP)
494 			signal = SIGILL;
495 	}
496 
497 #ifdef CONFIG_MATHEMU
498         if (signal == SIGFPE)
499 		do_fp_trap(regs, location,
500                            current->thread.fp_regs.fpc, interruption_code);
501         else if (signal == SIGSEGV) {
502 		info.si_signo = signal;
503 		info.si_errno = 0;
504 		info.si_code = SEGV_MAPERR;
505 		info.si_addr = (void __user *) location;
506 		do_trap(interruption_code, signal,
507 			"user address fault", regs, &info);
508 	} else
509 #endif
510         if (signal) {
511 		info.si_signo = signal;
512 		info.si_errno = 0;
513 		info.si_code = ILL_ILLOPC;
514 		info.si_addr = (void __user *) location;
515 		do_trap(interruption_code, signal,
516 			"illegal operation", regs, &info);
517 	}
518 }
519 
520 
521 #ifdef CONFIG_MATHEMU
522 asmlinkage void
523 specification_exception(struct pt_regs * regs, long interruption_code)
524 {
525         __u8 opcode[6];
526 	__u16 __user *location = NULL;
527 	int signal = 0;
528 
529 	location = (__u16 __user *) get_check_address(regs);
530 
531 	/*
532 	 * We got all needed information from the lowcore and can
533 	 * now safely switch on interrupts.
534 	 */
535         if (regs->psw.mask & PSW_MASK_PSTATE)
536 		local_irq_enable();
537 
538         if (regs->psw.mask & PSW_MASK_PSTATE) {
539 		get_user(*((__u16 *) opcode), location);
540 		switch (opcode[0]) {
541 		case 0x28: /* LDR Rx,Ry   */
542 			signal = math_emu_ldr(opcode);
543 			break;
544 		case 0x38: /* LER Rx,Ry   */
545 			signal = math_emu_ler(opcode);
546 			break;
547 		case 0x60: /* STD R,D(X,B) */
548 			get_user(*((__u16 *) (opcode+2)), location+1);
549 			signal = math_emu_std(opcode, regs);
550 			break;
551 		case 0x68: /* LD R,D(X,B) */
552 			get_user(*((__u16 *) (opcode+2)), location+1);
553 			signal = math_emu_ld(opcode, regs);
554 			break;
555 		case 0x70: /* STE R,D(X,B) */
556 			get_user(*((__u16 *) (opcode+2)), location+1);
557 			signal = math_emu_ste(opcode, regs);
558 			break;
559 		case 0x78: /* LE R,D(X,B) */
560 			get_user(*((__u16 *) (opcode+2)), location+1);
561 			signal = math_emu_le(opcode, regs);
562 			break;
563 		default:
564 			signal = SIGILL;
565 			break;
566                 }
567         } else
568 		signal = SIGILL;
569 
570         if (signal == SIGFPE)
571 		do_fp_trap(regs, location,
572                            current->thread.fp_regs.fpc, interruption_code);
573         else if (signal) {
574 		siginfo_t info;
575 		info.si_signo = signal;
576 		info.si_errno = 0;
577 		info.si_code = ILL_ILLOPN;
578 		info.si_addr = location;
579 		do_trap(interruption_code, signal,
580 			"specification exception", regs, &info);
581 	}
582 }
583 #else
584 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
585 	      ILL_ILLOPN, get_check_address(regs));
586 #endif
587 
588 static void data_exception(struct pt_regs * regs, long interruption_code)
589 {
590 	__u16 __user *location;
591 	int signal = 0;
592 
593 	location = get_check_address(regs);
594 
595 	/*
596 	 * We got all needed information from the lowcore and can
597 	 * now safely switch on interrupts.
598 	 */
599 	if (regs->psw.mask & PSW_MASK_PSTATE)
600 		local_irq_enable();
601 
602 	if (MACHINE_HAS_IEEE)
603 		asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
604 
605 #ifdef CONFIG_MATHEMU
606         else if (regs->psw.mask & PSW_MASK_PSTATE) {
607         	__u8 opcode[6];
608 		get_user(*((__u16 *) opcode), location);
609 		switch (opcode[0]) {
610 		case 0x28: /* LDR Rx,Ry   */
611 			signal = math_emu_ldr(opcode);
612 			break;
613 		case 0x38: /* LER Rx,Ry   */
614 			signal = math_emu_ler(opcode);
615 			break;
616 		case 0x60: /* STD R,D(X,B) */
617 			get_user(*((__u16 *) (opcode+2)), location+1);
618 			signal = math_emu_std(opcode, regs);
619 			break;
620 		case 0x68: /* LD R,D(X,B) */
621 			get_user(*((__u16 *) (opcode+2)), location+1);
622 			signal = math_emu_ld(opcode, regs);
623 			break;
624 		case 0x70: /* STE R,D(X,B) */
625 			get_user(*((__u16 *) (opcode+2)), location+1);
626 			signal = math_emu_ste(opcode, regs);
627 			break;
628 		case 0x78: /* LE R,D(X,B) */
629 			get_user(*((__u16 *) (opcode+2)), location+1);
630 			signal = math_emu_le(opcode, regs);
631 			break;
632 		case 0xb3:
633 			get_user(*((__u16 *) (opcode+2)), location+1);
634 			signal = math_emu_b3(opcode, regs);
635 			break;
636                 case 0xed:
637 			get_user(*((__u32 *) (opcode+2)),
638 				 (__u32 __user *)(location+1));
639 			signal = math_emu_ed(opcode, regs);
640 			break;
641 	        case 0xb2:
642 			if (opcode[1] == 0x99) {
643 				get_user(*((__u16 *) (opcode+2)), location+1);
644 				signal = math_emu_srnm(opcode, regs);
645 			} else if (opcode[1] == 0x9c) {
646 				get_user(*((__u16 *) (opcode+2)), location+1);
647 				signal = math_emu_stfpc(opcode, regs);
648 			} else if (opcode[1] == 0x9d) {
649 				get_user(*((__u16 *) (opcode+2)), location+1);
650 				signal = math_emu_lfpc(opcode, regs);
651 			} else
652 				signal = SIGILL;
653 			break;
654 		default:
655 			signal = SIGILL;
656 			break;
657                 }
658         }
659 #endif
660 	if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
661 		signal = SIGFPE;
662 	else
663 		signal = SIGILL;
664         if (signal == SIGFPE)
665 		do_fp_trap(regs, location,
666                            current->thread.fp_regs.fpc, interruption_code);
667         else if (signal) {
668 		siginfo_t info;
669 		info.si_signo = signal;
670 		info.si_errno = 0;
671 		info.si_code = ILL_ILLOPN;
672 		info.si_addr = location;
673 		do_trap(interruption_code, signal,
674 			"data exception", regs, &info);
675 	}
676 }
677 
678 static void space_switch_exception(struct pt_regs * regs, long int_code)
679 {
680         siginfo_t info;
681 
682 	/* Set user psw back to home space mode. */
683 	if (regs->psw.mask & PSW_MASK_PSTATE)
684 		regs->psw.mask |= PSW_ASC_HOME;
685 	/* Send SIGILL. */
686         info.si_signo = SIGILL;
687         info.si_errno = 0;
688         info.si_code = ILL_PRVOPC;
689         info.si_addr = get_check_address(regs);
690         do_trap(int_code, SIGILL, "space switch event", regs, &info);
691 }
692 
693 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
694 {
695 	bust_spinlocks(1);
696 	printk("Kernel stack overflow.\n");
697 	show_regs(regs);
698 	bust_spinlocks(0);
699 	panic("Corrupt kernel stack, can't continue.");
700 }
701 
702 /* init is done in lowcore.S and head.S */
703 
704 void __init trap_init(void)
705 {
706         int i;
707 
708         for (i = 0; i < 128; i++)
709           pgm_check_table[i] = &default_trap_handler;
710         pgm_check_table[1] = &illegal_op;
711         pgm_check_table[2] = &privileged_op;
712         pgm_check_table[3] = &execute_exception;
713         pgm_check_table[4] = &do_protection_exception;
714         pgm_check_table[5] = &addressing_exception;
715         pgm_check_table[6] = &specification_exception;
716         pgm_check_table[7] = &data_exception;
717         pgm_check_table[8] = &overflow_exception;
718         pgm_check_table[9] = &divide_exception;
719         pgm_check_table[0x0A] = &overflow_exception;
720         pgm_check_table[0x0B] = &divide_exception;
721         pgm_check_table[0x0C] = &hfp_overflow_exception;
722         pgm_check_table[0x0D] = &hfp_underflow_exception;
723         pgm_check_table[0x0E] = &hfp_significance_exception;
724         pgm_check_table[0x0F] = &hfp_divide_exception;
725         pgm_check_table[0x10] = &do_dat_exception;
726         pgm_check_table[0x11] = &do_dat_exception;
727         pgm_check_table[0x12] = &translation_exception;
728         pgm_check_table[0x13] = &special_op_exception;
729 #ifdef CONFIG_64BIT
730         pgm_check_table[0x38] = &do_dat_exception;
731 	pgm_check_table[0x39] = &do_dat_exception;
732 	pgm_check_table[0x3A] = &do_dat_exception;
733         pgm_check_table[0x3B] = &do_dat_exception;
734 #endif /* CONFIG_64BIT */
735         pgm_check_table[0x15] = &operand_exception;
736         pgm_check_table[0x1C] = &space_switch_exception;
737         pgm_check_table[0x1D] = &hfp_sqrt_exception;
738 	pgm_check_table[0x40] = &do_monitor_call;
739 	pfault_irq_init();
740 }
741