xref: /linux/arch/s390/kernel/traps.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
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/smp_lock.h>
26 #include <linux/init.h>
27 #include <linux/interrupt.h>
28 #include <linux/delay.h>
29 #include <linux/module.h>
30 #include <linux/kallsyms.h>
31 #include <linux/reboot.h>
32 #include <linux/kprobes.h>
33 
34 #include <asm/system.h>
35 #include <asm/uaccess.h>
36 #include <asm/io.h>
37 #include <asm/atomic.h>
38 #include <asm/mathemu.h>
39 #include <asm/cpcmd.h>
40 #include <asm/s390_ext.h>
41 #include <asm/lowcore.h>
42 #include <asm/debug.h>
43 #include <asm/kdebug.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 ATOMIC_NOTIFIER_HEAD(s390die_chain);
74 
75 int register_die_notifier(struct notifier_block *nb)
76 {
77 	return atomic_notifier_chain_register(&s390die_chain, nb);
78 }
79 EXPORT_SYMBOL(register_die_notifier);
80 
81 int unregister_die_notifier(struct notifier_block *nb)
82 {
83 	return atomic_notifier_chain_unregister(&s390die_chain, nb);
84 }
85 EXPORT_SYMBOL(unregister_die_notifier);
86 
87 /*
88  * For show_trace we have tree different stack to consider:
89  *   - the panic stack which is used if the kernel stack has overflown
90  *   - the asynchronous interrupt stack (cpu related)
91  *   - the synchronous kernel stack (process related)
92  * The stack trace can start at any of the three stack and can potentially
93  * touch all of them. The order is: panic stack, async stack, sync stack.
94  */
95 static unsigned long
96 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
97 {
98 	struct stack_frame *sf;
99 	struct pt_regs *regs;
100 
101 	while (1) {
102 		sp = sp & PSW_ADDR_INSN;
103 		if (sp < low || sp > high - sizeof(*sf))
104 			return sp;
105 		sf = (struct stack_frame *) sp;
106 		printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
107 		print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
108 		/* Follow the backchain. */
109 		while (1) {
110 			low = sp;
111 			sp = sf->back_chain & PSW_ADDR_INSN;
112 			if (!sp)
113 				break;
114 			if (sp <= low || sp > high - sizeof(*sf))
115 				return sp;
116 			sf = (struct stack_frame *) sp;
117 			printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
118 			print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
119 		}
120 		/* Zero backchain detected, check for interrupt frame. */
121 		sp = (unsigned long) (sf + 1);
122 		if (sp <= low || sp > high - sizeof(*regs))
123 			return sp;
124 		regs = (struct pt_regs *) sp;
125 		printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
126 		print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
127 		low = sp;
128 		sp = regs->gprs[15];
129 	}
130 }
131 
132 void show_trace(struct task_struct *task, unsigned long *stack)
133 {
134 	register unsigned long __r15 asm ("15");
135 	unsigned long sp;
136 
137 	sp = (unsigned long) stack;
138 	if (!sp)
139 		sp = task ? task->thread.ksp : __r15;
140 	printk("Call Trace:\n");
141 #ifdef CONFIG_CHECK_STACK
142 	sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
143 			  S390_lowcore.panic_stack);
144 #endif
145 	sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
146 			  S390_lowcore.async_stack);
147 	if (task)
148 		__show_trace(sp, (unsigned long) task_stack_page(task),
149 			     (unsigned long) task_stack_page(task) + THREAD_SIZE);
150 	else
151 		__show_trace(sp, S390_lowcore.thread_info,
152 			     S390_lowcore.thread_info + THREAD_SIZE);
153 	printk("\n");
154 	if (!task)
155 		task = current;
156 	debug_show_held_locks(task);
157 }
158 
159 void show_stack(struct task_struct *task, unsigned long *sp)
160 {
161 	register unsigned long * __r15 asm ("15");
162 	unsigned long *stack;
163 	int i;
164 
165 	if (!sp)
166 		stack = task ? (unsigned long *) task->thread.ksp : __r15;
167 	else
168 		stack = sp;
169 
170 	for (i = 0; i < kstack_depth_to_print; i++) {
171 		if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
172 			break;
173 		if (i && ((i * sizeof (long) % 32) == 0))
174 			printk("\n       ");
175 		printk("%p ", (void *)*stack++);
176 	}
177 	printk("\n");
178 	show_trace(task, sp);
179 }
180 
181 /*
182  * The architecture-independent dump_stack generator
183  */
184 void dump_stack(void)
185 {
186 	show_stack(NULL, NULL);
187 }
188 
189 EXPORT_SYMBOL(dump_stack);
190 
191 void show_registers(struct pt_regs *regs)
192 {
193 	mm_segment_t old_fs;
194 	char *mode;
195 	int i;
196 
197 	mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
198 	printk("%s PSW : %p %p",
199 	       mode, (void *) regs->psw.mask,
200 	       (void *) regs->psw.addr);
201 	print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
202 	printk("%s GPRS: " FOURLONG, mode,
203 	       regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
204 	printk("           " FOURLONG,
205 	       regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
206 	printk("           " FOURLONG,
207 	       regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
208 	printk("           " FOURLONG,
209 	       regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
210 
211 #if 0
212 	/* FIXME: this isn't needed any more but it changes the ksymoops
213 	 * input. To remove or not to remove ... */
214 	save_access_regs(regs->acrs);
215 	printk("%s ACRS: %08x %08x %08x %08x\n", mode,
216 	       regs->acrs[0], regs->acrs[1], regs->acrs[2], regs->acrs[3]);
217 	printk("           %08x %08x %08x %08x\n",
218 	       regs->acrs[4], regs->acrs[5], regs->acrs[6], regs->acrs[7]);
219 	printk("           %08x %08x %08x %08x\n",
220 	       regs->acrs[8], regs->acrs[9], regs->acrs[10], regs->acrs[11]);
221 	printk("           %08x %08x %08x %08x\n",
222 	       regs->acrs[12], regs->acrs[13], regs->acrs[14], regs->acrs[15]);
223 #endif
224 
225 	/*
226 	 * Print the first 20 byte of the instruction stream at the
227 	 * time of the fault.
228 	 */
229 	old_fs = get_fs();
230 	if (regs->psw.mask & PSW_MASK_PSTATE)
231 		set_fs(USER_DS);
232 	else
233 		set_fs(KERNEL_DS);
234 	printk("%s Code: ", mode);
235 	for (i = 0; i < 20; i++) {
236 		unsigned char c;
237 		if (__get_user(c, (char __user *)(regs->psw.addr + i))) {
238 			printk(" Bad PSW.");
239 			break;
240 		}
241 		printk("%02x ", c);
242 	}
243 	set_fs(old_fs);
244 
245 	printk("\n");
246 }
247 
248 /* This is called from fs/proc/array.c */
249 char *task_show_regs(struct task_struct *task, char *buffer)
250 {
251 	struct pt_regs *regs;
252 
253 	regs = task_pt_regs(task);
254 	buffer += sprintf(buffer, "task: %p, ksp: %p\n",
255 		       task, (void *)task->thread.ksp);
256 	buffer += sprintf(buffer, "User PSW : %p %p\n",
257 		       (void *) regs->psw.mask, (void *)regs->psw.addr);
258 
259 	buffer += sprintf(buffer, "User GPRS: " FOURLONG,
260 			  regs->gprs[0], regs->gprs[1],
261 			  regs->gprs[2], regs->gprs[3]);
262 	buffer += sprintf(buffer, "           " FOURLONG,
263 			  regs->gprs[4], regs->gprs[5],
264 			  regs->gprs[6], regs->gprs[7]);
265 	buffer += sprintf(buffer, "           " FOURLONG,
266 			  regs->gprs[8], regs->gprs[9],
267 			  regs->gprs[10], regs->gprs[11]);
268 	buffer += sprintf(buffer, "           " FOURLONG,
269 			  regs->gprs[12], regs->gprs[13],
270 			  regs->gprs[14], regs->gprs[15]);
271 	buffer += sprintf(buffer, "User ACRS: %08x %08x %08x %08x\n",
272 			  task->thread.acrs[0], task->thread.acrs[1],
273 			  task->thread.acrs[2], task->thread.acrs[3]);
274 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
275 			  task->thread.acrs[4], task->thread.acrs[5],
276 			  task->thread.acrs[6], task->thread.acrs[7]);
277 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
278 			  task->thread.acrs[8], task->thread.acrs[9],
279 			  task->thread.acrs[10], task->thread.acrs[11]);
280 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
281 			  task->thread.acrs[12], task->thread.acrs[13],
282 			  task->thread.acrs[14], task->thread.acrs[15]);
283 	return buffer;
284 }
285 
286 static DEFINE_SPINLOCK(die_lock);
287 
288 void die(const char * str, struct pt_regs * regs, long err)
289 {
290 	static int die_counter;
291 
292 	debug_stop_all();
293 	console_verbose();
294 	spin_lock_irq(&die_lock);
295 	bust_spinlocks(1);
296 	printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
297         show_regs(regs);
298 	bust_spinlocks(0);
299         spin_unlock_irq(&die_lock);
300 	if (in_interrupt())
301 		panic("Fatal exception in interrupt");
302 	if (panic_on_oops)
303 		panic("Fatal exception: panic_on_oops");
304         do_exit(SIGSEGV);
305 }
306 
307 static void inline
308 report_user_fault(long interruption_code, struct pt_regs *regs)
309 {
310 #if defined(CONFIG_SYSCTL)
311 	if (!sysctl_userprocess_debug)
312 		return;
313 #endif
314 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
315 	printk("User process fault: interruption code 0x%lX\n",
316 	       interruption_code);
317 	show_regs(regs);
318 #endif
319 }
320 
321 static void __kprobes inline do_trap(long interruption_code, int signr,
322 					char *str, struct pt_regs *regs,
323 					siginfo_t *info)
324 {
325 	/*
326 	 * We got all needed information from the lowcore and can
327 	 * now safely switch on interrupts.
328 	 */
329         if (regs->psw.mask & PSW_MASK_PSTATE)
330 		local_irq_enable();
331 
332 	if (notify_die(DIE_TRAP, str, regs, interruption_code,
333 				interruption_code, signr) == NOTIFY_STOP)
334 		return;
335 
336         if (regs->psw.mask & PSW_MASK_PSTATE) {
337                 struct task_struct *tsk = current;
338 
339                 tsk->thread.trap_no = interruption_code & 0xffff;
340 		force_sig_info(signr, info, tsk);
341 		report_user_fault(interruption_code, regs);
342         } else {
343                 const struct exception_table_entry *fixup;
344                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
345                 if (fixup)
346                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
347                 else
348                         die(str, regs, interruption_code);
349         }
350 }
351 
352 static inline void __user *get_check_address(struct pt_regs *regs)
353 {
354 	return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
355 }
356 
357 void __kprobes do_single_step(struct pt_regs *regs)
358 {
359 	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
360 					SIGTRAP) == NOTIFY_STOP){
361 		return;
362 	}
363 	if ((current->ptrace & PT_PTRACED) != 0)
364 		force_sig(SIGTRAP, current);
365 }
366 
367 static void default_trap_handler(struct pt_regs * regs, long interruption_code)
368 {
369         if (regs->psw.mask & PSW_MASK_PSTATE) {
370 		local_irq_enable();
371 		do_exit(SIGSEGV);
372 		report_user_fault(interruption_code, regs);
373 	} else
374 		die("Unknown program exception", regs, interruption_code);
375 }
376 
377 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
378 static void name(struct pt_regs * regs, long interruption_code) \
379 { \
380         siginfo_t info; \
381         info.si_signo = signr; \
382         info.si_errno = 0; \
383         info.si_code = sicode; \
384 	info.si_addr = siaddr; \
385         do_trap(interruption_code, signr, str, regs, &info); \
386 }
387 
388 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
389 	      ILL_ILLADR, get_check_address(regs))
390 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
391 	      ILL_ILLOPN, get_check_address(regs))
392 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
393 	      FPE_INTDIV, get_check_address(regs))
394 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
395 	      FPE_INTOVF, get_check_address(regs))
396 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
397 	      FPE_FLTOVF, get_check_address(regs))
398 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
399 	      FPE_FLTUND, get_check_address(regs))
400 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
401 	      FPE_FLTRES, get_check_address(regs))
402 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
403 	      FPE_FLTDIV, get_check_address(regs))
404 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
405 	      FPE_FLTINV, get_check_address(regs))
406 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
407 	      ILL_ILLOPN, get_check_address(regs))
408 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
409 	      ILL_PRVOPC, get_check_address(regs))
410 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
411 	      ILL_ILLOPN, get_check_address(regs))
412 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
413 	      ILL_ILLOPN, get_check_address(regs))
414 
415 static inline void
416 do_fp_trap(struct pt_regs *regs, void __user *location,
417            int fpc, long interruption_code)
418 {
419 	siginfo_t si;
420 
421 	si.si_signo = SIGFPE;
422 	si.si_errno = 0;
423 	si.si_addr = location;
424 	si.si_code = 0;
425 	/* FPC[2] is Data Exception Code */
426 	if ((fpc & 0x00000300) == 0) {
427 		/* bits 6 and 7 of DXC are 0 iff IEEE exception */
428 		if (fpc & 0x8000) /* invalid fp operation */
429 			si.si_code = FPE_FLTINV;
430 		else if (fpc & 0x4000) /* div by 0 */
431 			si.si_code = FPE_FLTDIV;
432 		else if (fpc & 0x2000) /* overflow */
433 			si.si_code = FPE_FLTOVF;
434 		else if (fpc & 0x1000) /* underflow */
435 			si.si_code = FPE_FLTUND;
436 		else if (fpc & 0x0800) /* inexact */
437 			si.si_code = FPE_FLTRES;
438 	}
439 	current->thread.ieee_instruction_pointer = (addr_t) location;
440 	do_trap(interruption_code, SIGFPE,
441 		"floating point exception", regs, &si);
442 }
443 
444 static void illegal_op(struct pt_regs * regs, long interruption_code)
445 {
446 	siginfo_t info;
447         __u8 opcode[6];
448 	__u16 __user *location;
449 	int signal = 0;
450 
451 	location = get_check_address(regs);
452 
453 	/*
454 	 * We got all needed information from the lowcore and can
455 	 * now safely switch on interrupts.
456 	 */
457 	if (regs->psw.mask & PSW_MASK_PSTATE)
458 		local_irq_enable();
459 
460 	if (regs->psw.mask & PSW_MASK_PSTATE) {
461 		if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
462 			return;
463 		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
464 			if (current->ptrace & PT_PTRACED)
465 				force_sig(SIGTRAP, current);
466 			else
467 				signal = SIGILL;
468 #ifdef CONFIG_MATHEMU
469 		} else if (opcode[0] == 0xb3) {
470 			if (get_user(*((__u16 *) (opcode+2)), location+1))
471 				return;
472 			signal = math_emu_b3(opcode, regs);
473                 } else if (opcode[0] == 0xed) {
474 			if (get_user(*((__u32 *) (opcode+2)),
475 				     (__u32 __user *)(location+1)))
476 				return;
477 			signal = math_emu_ed(opcode, regs);
478 		} else if (*((__u16 *) opcode) == 0xb299) {
479 			if (get_user(*((__u16 *) (opcode+2)), location+1))
480 				return;
481 			signal = math_emu_srnm(opcode, regs);
482 		} else if (*((__u16 *) opcode) == 0xb29c) {
483 			if (get_user(*((__u16 *) (opcode+2)), location+1))
484 				return;
485 			signal = math_emu_stfpc(opcode, regs);
486 		} else if (*((__u16 *) opcode) == 0xb29d) {
487 			if (get_user(*((__u16 *) (opcode+2)), location+1))
488 				return;
489 			signal = math_emu_lfpc(opcode, regs);
490 #endif
491 		} else
492 			signal = SIGILL;
493 	} else {
494 		/*
495 		 * If we get an illegal op in kernel mode, send it through the
496 		 * kprobes notifier. If kprobes doesn't pick it up, SIGILL
497 		 */
498 		if (notify_die(DIE_BPT, "bpt", regs, interruption_code,
499 			       3, SIGTRAP) != NOTIFY_STOP)
500 			signal = SIGILL;
501 	}
502 
503 #ifdef CONFIG_MATHEMU
504         if (signal == SIGFPE)
505 		do_fp_trap(regs, location,
506                            current->thread.fp_regs.fpc, interruption_code);
507         else if (signal == SIGSEGV) {
508 		info.si_signo = signal;
509 		info.si_errno = 0;
510 		info.si_code = SEGV_MAPERR;
511 		info.si_addr = (void __user *) location;
512 		do_trap(interruption_code, signal,
513 			"user address fault", regs, &info);
514 	} else
515 #endif
516         if (signal) {
517 		info.si_signo = signal;
518 		info.si_errno = 0;
519 		info.si_code = ILL_ILLOPC;
520 		info.si_addr = (void __user *) location;
521 		do_trap(interruption_code, signal,
522 			"illegal operation", regs, &info);
523 	}
524 }
525 
526 
527 #ifdef CONFIG_MATHEMU
528 asmlinkage void
529 specification_exception(struct pt_regs * regs, long interruption_code)
530 {
531         __u8 opcode[6];
532 	__u16 __user *location = NULL;
533 	int signal = 0;
534 
535 	location = (__u16 __user *) get_check_address(regs);
536 
537 	/*
538 	 * We got all needed information from the lowcore and can
539 	 * now safely switch on interrupts.
540 	 */
541         if (regs->psw.mask & PSW_MASK_PSTATE)
542 		local_irq_enable();
543 
544         if (regs->psw.mask & PSW_MASK_PSTATE) {
545 		get_user(*((__u16 *) opcode), location);
546 		switch (opcode[0]) {
547 		case 0x28: /* LDR Rx,Ry   */
548 			signal = math_emu_ldr(opcode);
549 			break;
550 		case 0x38: /* LER Rx,Ry   */
551 			signal = math_emu_ler(opcode);
552 			break;
553 		case 0x60: /* STD R,D(X,B) */
554 			get_user(*((__u16 *) (opcode+2)), location+1);
555 			signal = math_emu_std(opcode, regs);
556 			break;
557 		case 0x68: /* LD R,D(X,B) */
558 			get_user(*((__u16 *) (opcode+2)), location+1);
559 			signal = math_emu_ld(opcode, regs);
560 			break;
561 		case 0x70: /* STE R,D(X,B) */
562 			get_user(*((__u16 *) (opcode+2)), location+1);
563 			signal = math_emu_ste(opcode, regs);
564 			break;
565 		case 0x78: /* LE R,D(X,B) */
566 			get_user(*((__u16 *) (opcode+2)), location+1);
567 			signal = math_emu_le(opcode, regs);
568 			break;
569 		default:
570 			signal = SIGILL;
571 			break;
572                 }
573         } else
574 		signal = SIGILL;
575 
576         if (signal == SIGFPE)
577 		do_fp_trap(regs, location,
578                            current->thread.fp_regs.fpc, interruption_code);
579         else if (signal) {
580 		siginfo_t info;
581 		info.si_signo = signal;
582 		info.si_errno = 0;
583 		info.si_code = ILL_ILLOPN;
584 		info.si_addr = location;
585 		do_trap(interruption_code, signal,
586 			"specification exception", regs, &info);
587 	}
588 }
589 #else
590 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
591 	      ILL_ILLOPN, get_check_address(regs));
592 #endif
593 
594 static void data_exception(struct pt_regs * regs, long interruption_code)
595 {
596 	__u16 __user *location;
597 	int signal = 0;
598 
599 	location = get_check_address(regs);
600 
601 	/*
602 	 * We got all needed information from the lowcore and can
603 	 * now safely switch on interrupts.
604 	 */
605 	if (regs->psw.mask & PSW_MASK_PSTATE)
606 		local_irq_enable();
607 
608 	if (MACHINE_HAS_IEEE)
609 		asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
610 
611 #ifdef CONFIG_MATHEMU
612         else if (regs->psw.mask & PSW_MASK_PSTATE) {
613         	__u8 opcode[6];
614 		get_user(*((__u16 *) opcode), location);
615 		switch (opcode[0]) {
616 		case 0x28: /* LDR Rx,Ry   */
617 			signal = math_emu_ldr(opcode);
618 			break;
619 		case 0x38: /* LER Rx,Ry   */
620 			signal = math_emu_ler(opcode);
621 			break;
622 		case 0x60: /* STD R,D(X,B) */
623 			get_user(*((__u16 *) (opcode+2)), location+1);
624 			signal = math_emu_std(opcode, regs);
625 			break;
626 		case 0x68: /* LD R,D(X,B) */
627 			get_user(*((__u16 *) (opcode+2)), location+1);
628 			signal = math_emu_ld(opcode, regs);
629 			break;
630 		case 0x70: /* STE R,D(X,B) */
631 			get_user(*((__u16 *) (opcode+2)), location+1);
632 			signal = math_emu_ste(opcode, regs);
633 			break;
634 		case 0x78: /* LE R,D(X,B) */
635 			get_user(*((__u16 *) (opcode+2)), location+1);
636 			signal = math_emu_le(opcode, regs);
637 			break;
638 		case 0xb3:
639 			get_user(*((__u16 *) (opcode+2)), location+1);
640 			signal = math_emu_b3(opcode, regs);
641 			break;
642                 case 0xed:
643 			get_user(*((__u32 *) (opcode+2)),
644 				 (__u32 __user *)(location+1));
645 			signal = math_emu_ed(opcode, regs);
646 			break;
647 	        case 0xb2:
648 			if (opcode[1] == 0x99) {
649 				get_user(*((__u16 *) (opcode+2)), location+1);
650 				signal = math_emu_srnm(opcode, regs);
651 			} else if (opcode[1] == 0x9c) {
652 				get_user(*((__u16 *) (opcode+2)), location+1);
653 				signal = math_emu_stfpc(opcode, regs);
654 			} else if (opcode[1] == 0x9d) {
655 				get_user(*((__u16 *) (opcode+2)), location+1);
656 				signal = math_emu_lfpc(opcode, regs);
657 			} else
658 				signal = SIGILL;
659 			break;
660 		default:
661 			signal = SIGILL;
662 			break;
663                 }
664         }
665 #endif
666 	if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
667 		signal = SIGFPE;
668 	else
669 		signal = SIGILL;
670         if (signal == SIGFPE)
671 		do_fp_trap(regs, location,
672                            current->thread.fp_regs.fpc, interruption_code);
673         else if (signal) {
674 		siginfo_t info;
675 		info.si_signo = signal;
676 		info.si_errno = 0;
677 		info.si_code = ILL_ILLOPN;
678 		info.si_addr = location;
679 		do_trap(interruption_code, signal,
680 			"data exception", regs, &info);
681 	}
682 }
683 
684 static void space_switch_exception(struct pt_regs * regs, long int_code)
685 {
686         siginfo_t info;
687 
688 	/* Set user psw back to home space mode. */
689 	if (regs->psw.mask & PSW_MASK_PSTATE)
690 		regs->psw.mask |= PSW_ASC_HOME;
691 	/* Send SIGILL. */
692         info.si_signo = SIGILL;
693         info.si_errno = 0;
694         info.si_code = ILL_PRVOPC;
695         info.si_addr = get_check_address(regs);
696         do_trap(int_code, SIGILL, "space switch event", regs, &info);
697 }
698 
699 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
700 {
701 	bust_spinlocks(1);
702 	printk("Kernel stack overflow.\n");
703 	show_regs(regs);
704 	bust_spinlocks(0);
705 	panic("Corrupt kernel stack, can't continue.");
706 }
707 
708 /* init is done in lowcore.S and head.S */
709 
710 void __init trap_init(void)
711 {
712         int i;
713 
714         for (i = 0; i < 128; i++)
715           pgm_check_table[i] = &default_trap_handler;
716         pgm_check_table[1] = &illegal_op;
717         pgm_check_table[2] = &privileged_op;
718         pgm_check_table[3] = &execute_exception;
719         pgm_check_table[4] = &do_protection_exception;
720         pgm_check_table[5] = &addressing_exception;
721         pgm_check_table[6] = &specification_exception;
722         pgm_check_table[7] = &data_exception;
723         pgm_check_table[8] = &overflow_exception;
724         pgm_check_table[9] = &divide_exception;
725         pgm_check_table[0x0A] = &overflow_exception;
726         pgm_check_table[0x0B] = &divide_exception;
727         pgm_check_table[0x0C] = &hfp_overflow_exception;
728         pgm_check_table[0x0D] = &hfp_underflow_exception;
729         pgm_check_table[0x0E] = &hfp_significance_exception;
730         pgm_check_table[0x0F] = &hfp_divide_exception;
731         pgm_check_table[0x10] = &do_dat_exception;
732         pgm_check_table[0x11] = &do_dat_exception;
733         pgm_check_table[0x12] = &translation_exception;
734         pgm_check_table[0x13] = &special_op_exception;
735 #ifdef CONFIG_64BIT
736         pgm_check_table[0x38] = &do_dat_exception;
737 	pgm_check_table[0x39] = &do_dat_exception;
738 	pgm_check_table[0x3A] = &do_dat_exception;
739         pgm_check_table[0x3B] = &do_dat_exception;
740 #endif /* CONFIG_64BIT */
741         pgm_check_table[0x15] = &operand_exception;
742         pgm_check_table[0x1C] = &space_switch_exception;
743         pgm_check_table[0x1D] = &hfp_sqrt_exception;
744 	pgm_check_table[0x40] = &do_monitor_call;
745 	pfault_irq_init();
746 }
747