1 /*
2  *  linux/arch/parisc/traps.c
3  *
4  *  Copyright (C) 1991, 1992  Linus Torvalds
5  *  Copyright (C) 1999, 2000  Philipp Rumpf <prumpf@tux.org>
6  */
7 
8 /*
9  * 'Traps.c' handles hardware traps and faults after we have saved some
10  * state in 'asm.s'.
11  */
12 
13 #include <linux/config.h>
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
16 #include <linux/string.h>
17 #include <linux/errno.h>
18 #include <linux/ptrace.h>
19 #include <linux/timer.h>
20 #include <linux/mm.h>
21 #include <linux/module.h>
22 #include <linux/smp.h>
23 #include <linux/smp_lock.h>
24 #include <linux/spinlock.h>
25 #include <linux/init.h>
26 #include <linux/interrupt.h>
27 #include <linux/console.h>
28 
29 #include <asm/system.h>
30 #include <asm/uaccess.h>
31 #include <asm/io.h>
32 #include <asm/irq.h>
33 #include <asm/traps.h>
34 #include <asm/unaligned.h>
35 #include <asm/atomic.h>
36 #include <asm/smp.h>
37 #include <asm/pdc.h>
38 #include <asm/pdc_chassis.h>
39 
40 #include "../math-emu/math-emu.h"	/* for handle_fpe() */
41 
42 #define PRINT_USER_FAULTS /* (turn this on if you want user faults to be */
43 			  /*  dumped to the console via printk)          */
44 
printbinary(char * buf,unsigned long x,int nbits)45 static int printbinary(char *buf, unsigned long x, int nbits)
46 {
47 	unsigned long mask = 1UL << (nbits - 1);
48 	while (mask != 0) {
49 		*buf++ = (mask & x ? '1' : '0');
50 		mask >>= 1;
51 	}
52 	*buf = '\0';
53 
54 	return nbits;
55 }
56 
57 #ifdef __LP64__
58 #define RFMT "%016lx"
59 #else
60 #define RFMT "%08lx"
61 #endif
62 
63 static int kstack_depth_to_print = 24;
64 extern struct module *module_list;
65 extern struct module kernel_module;
66 
kernel_text_address(unsigned long addr)67 static inline int kernel_text_address(unsigned long addr)
68 {
69 #ifdef CONFIG_MODULES
70 	int retval = 0;
71 	struct module *mod;
72 #endif
73 	extern char _stext, _etext;
74 
75 	if (addr >= (unsigned long) &_stext &&
76 	    addr <= (unsigned long) &_etext)
77 		return 1;
78 
79 #ifdef CONFIG_MODULES
80 	for (mod = module_list; mod != &kernel_module; mod = mod->next) {
81 		/* mod_bound tests for addr being inside the vmalloc'ed
82 		 * module area. Of course it'd be better to test only
83 		 * for the .text subset... */
84 		if (mod_bound(addr, 0, mod)) {
85 			retval = 1;
86 			break;
87 		}
88 	}
89 	return retval;
90 #endif
91 }
92 
93 
show_trace(unsigned long * stack)94 void show_trace(unsigned long * stack)
95 {
96 	unsigned long *startstack;
97 	unsigned long addr;
98 	int i;
99 
100 	startstack = (unsigned long *)((unsigned long)stack & ~(THREAD_SIZE - 1));
101 	i = 1;
102 	printk("Kernel addresses on the stack:\n");
103 	while (stack >= startstack) {
104 		addr = *stack--;
105 		if (kernel_text_address(addr)) {
106 			printk(" [<" RFMT ">] ", addr);
107 			if ((i & 0x03) == 0)
108 				printk("\n");
109 			i++;
110 		}
111 	}
112 	printk("\n");
113 }
114 
show_trace_task(struct task_struct * tsk)115 void show_trace_task(struct task_struct *tsk)
116 {
117 	show_trace((unsigned long *)tsk->thread.regs.ksp);
118 }
119 
show_stack(unsigned long * sp)120 void show_stack(unsigned long * sp)
121 {
122 	unsigned long *stack;
123 	int i;
124 
125 	/*
126 	 * debugging aid: "show_stack(NULL);" prints the
127 	 * back trace for this cpu.
128 	 */
129 	if (sp==NULL)
130 		sp = (unsigned long*)&sp;
131 
132 	stack = sp;
133 	printk("\n" KERN_CRIT "Stack Dump:\n");
134 	printk(KERN_CRIT " " RFMT ":  ", (unsigned long) stack);
135 	for (i=0; i < kstack_depth_to_print; i++) {
136 		if (((long) stack & (THREAD_SIZE-1)) == 0)
137 			break;
138 		if (i && ((i & 0x03) == 0))
139 			printk("\n" KERN_CRIT " " RFMT ":  ",
140 				(unsigned long) stack);
141 		printk(RFMT " ", *stack--);
142 	}
143 	printk("\n" KERN_CRIT "\n");
144 	show_trace(sp);
145 }
146 
147 /*
148  * The architecture-independent backtrace generator
149  */
dump_stack(void)150 void dump_stack(void)
151 {
152 	show_stack(0);
153 }
154 
155 
show_regs(struct pt_regs * regs)156 void show_regs(struct pt_regs *regs)
157 {
158 	int i;
159 	char buf[128], *p;
160 	char *level;
161 	unsigned long cr30;
162 	unsigned long cr31;
163 
164 	level = user_mode(regs) ? KERN_DEBUG : KERN_CRIT;
165 
166 	printk("%s\n", level); /* don't want to have that pretty register dump messed up */
167 
168 	printk("%s     YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI\n", level);
169 	printbinary(buf, regs->gr[0], 32);
170 	printk("%sPSW: %s %s\n", level, buf, print_tainted());
171 
172 	for (i = 0; i < 32; i += 4) {
173 		int j;
174 		p = buf;
175 		p += sprintf(p, "%sr%02d-%02d ", level, i, i + 3);
176 		for (j = 0; j < 4; j++) {
177 			p += sprintf(p, " " RFMT, (i+j) == 0 ? 0 : regs->gr[i + j]);
178 		}
179 		printk("%s\n", buf);
180 	}
181 
182 	for (i = 0; i < 8; i += 4) {
183 		int j;
184 		p = buf;
185 		p += sprintf(p, "%ssr%d-%d  ", level, i, i + 3);
186 		for (j = 0; j < 4; j++) {
187 			p += sprintf(p, " " RFMT, regs->sr[i + j]);
188 		}
189 		printk("%s\n", buf);
190 	}
191 
192 #if RIDICULOUSLY_VERBOSE
193 	for (i = 0; i < 32; i += 2)
194 		printk("%sFR%02d : %016lx  FR%2d : %016lx", level, i,
195 				regs->fr[i], i+1, regs->fr[i+1]);
196 #endif
197 
198 	cr30 = mfctl(30);
199 	cr31 = mfctl(31);
200 	printk("%s\n", level);
201 	printk("%sIASQ: " RFMT " " RFMT " IAOQ: " RFMT " " RFMT "\n",
202 	       level, regs->iasq[0], regs->iasq[1], regs->iaoq[0], regs->iaoq[1]);
203 	printk("%s IIR: %08lx    ISR: " RFMT "  IOR: " RFMT "\n",
204 	       level, regs->iir, regs->isr, regs->ior);
205 	printk("%s CPU: %8d   CR30: " RFMT " CR31: " RFMT "\n",
206 	       level, ((struct task_struct *)cr30)->processor, cr30, cr31);
207 	printk("%s ORIG_R28: " RFMT "\n", level, regs->orig_r28);
208 }
209 
210 
die_if_kernel(char * str,struct pt_regs * regs,long err)211 void die_if_kernel(char *str, struct pt_regs *regs, long err)
212 {
213 	if (user_mode(regs)) {
214 #ifdef PRINT_USER_FAULTS
215 		if (err == 0)
216 			return; /* STFU */
217 
218 		/* XXX for debugging only */
219 		printk(KERN_DEBUG "%s (pid %d): %s (code %ld)\n",
220 			current->comm, current->pid, str, err);
221 		show_regs(regs);
222 #endif
223 		return;
224 	}
225 
226 	/* unlock the pdc lock if necessary */
227 	pdc_emergency_unlock();
228 
229 	/* maybe the kernel hasn't booted very far yet and hasn't been able
230 	 * to initialize the serial or STI console. In that case we should
231 	 * re-enable the pdc console, so that the user will be able to
232 	 * identify the problem. */
233 	if (!console_drivers)
234 		pdc_console_restart();
235 
236 	printk(KERN_CRIT "%s (pid %d): %s (code %ld)\n",
237 		current->comm, current->pid, str, err);
238 	show_regs(regs);
239 
240 	/* Wot's wrong wif bein' racy? */
241 	if (current->thread.flags & PARISC_KERNEL_DEATH) {
242 		printk(KERN_CRIT "%s() recursion detected.\n", __FUNCTION__);
243 		sti();
244 		while (1);
245 	}
246 
247 	current->thread.flags |= PARISC_KERNEL_DEATH;
248 	do_exit(SIGSEGV);
249 }
250 
syscall_ipi(int (* syscall)(struct pt_regs *),struct pt_regs * regs)251 int syscall_ipi(int (*syscall) (struct pt_regs *), struct pt_regs *regs)
252 {
253 	return syscall(regs);
254 }
255 
256 /* gdb uses break 4,8 */
257 #define GDB_BREAK_INSN 0x10004
handle_gdb_break(struct pt_regs * regs,int wot)258 void handle_gdb_break(struct pt_regs *regs, int wot)
259 {
260 	struct siginfo si;
261 
262 	si.si_code = wot;
263 	si.si_addr = (void *) (regs->iaoq[0] & ~3);
264 	si.si_signo = SIGTRAP;
265 	si.si_errno = 0;
266 	force_sig_info(SIGTRAP, &si, current);
267 }
268 
handle_break(unsigned iir,struct pt_regs * regs)269 void handle_break(unsigned iir, struct pt_regs *regs)
270 {
271 	struct siginfo si;
272 
273 	switch(iir) {
274 	case 0x00:
275 #ifdef PRINT_USER_FAULTS
276 		printk(KERN_DEBUG "break 0,0: pid=%d command='%s'\n",
277 		       current->pid, current->comm);
278 #endif
279 		die_if_kernel("Breakpoint", regs, 0);
280 #ifdef PRINT_USER_FAULTS
281 		show_regs(regs);
282 #endif
283 		si.si_code = TRAP_BRKPT;
284 		si.si_addr = (void *) (regs->iaoq[0] & ~3);
285 		si.si_signo = SIGTRAP;
286 		force_sig_info(SIGTRAP, &si, current);
287 		break;
288 
289 	case GDB_BREAK_INSN:
290 		die_if_kernel("Breakpoint", regs, 0);
291 		handle_gdb_break(regs, TRAP_BRKPT);
292 		break;
293 
294 	default:
295 #ifdef PRINT_USER_FAULTS
296 		printk(KERN_DEBUG "break %#08x: pid=%d command='%s'\n",
297 		       iir, current->pid, current->comm);
298 		show_regs(regs);
299 #endif
300 		si.si_signo = SIGTRAP;
301 		si.si_code = TRAP_BRKPT;
302 		si.si_addr = (void *) (regs->iaoq[0] & ~3);
303 		force_sig_info(SIGTRAP, &si, current);
304 		return;
305 	}
306 }
307 
308 
handle_toc(void)309 int handle_toc(void)
310 {
311 	printk(KERN_CRIT "TOC call.\n");
312 	return 0;
313 }
314 
default_trap(int code,struct pt_regs * regs)315 static void default_trap(int code, struct pt_regs *regs)
316 {
317 	printk(KERN_ERR "Trap %d on CPU %d\n", code, smp_processor_id());
318 	show_regs(regs);
319 }
320 
321 void (*cpu_lpmc) (int code, struct pt_regs *regs) = default_trap;
322 
323 
transfer_pim_to_trap_frame(struct pt_regs * regs)324 void transfer_pim_to_trap_frame(struct pt_regs *regs)
325 {
326     register int i;
327     extern unsigned int hpmc_pim_data[];
328     struct pdc_hpmc_pim_11 *pim_narrow;
329     struct pdc_hpmc_pim_20 *pim_wide;
330 
331     if (boot_cpu_data.cpu_type >= pcxu) {
332 
333 	pim_wide = (struct pdc_hpmc_pim_20 *)hpmc_pim_data;
334 
335 	/*
336 	 * Note: The following code will probably generate a
337 	 * bunch of truncation error warnings from the compiler.
338 	 * Could be handled with an ifdef, but perhaps there
339 	 * is a better way.
340 	 */
341 
342 	regs->gr[0] = pim_wide->cr[22];
343 
344 	for (i = 1; i < 32; i++)
345 	    regs->gr[i] = pim_wide->gr[i];
346 
347 	for (i = 0; i < 32; i++)
348 	    regs->fr[i] = pim_wide->fr[i];
349 
350 	for (i = 0; i < 8; i++)
351 	    regs->sr[i] = pim_wide->sr[i];
352 
353 	regs->iasq[0] = pim_wide->cr[17];
354 	regs->iasq[1] = pim_wide->iasq_back;
355 	regs->iaoq[0] = pim_wide->cr[18];
356 	regs->iaoq[1] = pim_wide->iaoq_back;
357 
358 	regs->sar  = pim_wide->cr[11];
359 	regs->iir  = pim_wide->cr[19];
360 	regs->isr  = pim_wide->cr[20];
361 	regs->ior  = pim_wide->cr[21];
362     }
363     else {
364 	pim_narrow = (struct pdc_hpmc_pim_11 *)hpmc_pim_data;
365 
366 	regs->gr[0] = pim_narrow->cr[22];
367 
368 	for (i = 1; i < 32; i++)
369 	    regs->gr[i] = pim_narrow->gr[i];
370 
371 	for (i = 0; i < 32; i++)
372 	    regs->fr[i] = pim_narrow->fr[i];
373 
374 	for (i = 0; i < 8; i++)
375 	    regs->sr[i] = pim_narrow->sr[i];
376 
377 	regs->iasq[0] = pim_narrow->cr[17];
378 	regs->iasq[1] = pim_narrow->iasq_back;
379 	regs->iaoq[0] = pim_narrow->cr[18];
380 	regs->iaoq[1] = pim_narrow->iaoq_back;
381 
382 	regs->sar  = pim_narrow->cr[11];
383 	regs->iir  = pim_narrow->cr[19];
384 	regs->isr  = pim_narrow->cr[20];
385 	regs->ior  = pim_narrow->cr[21];
386     }
387 
388     /*
389      * The following fields only have meaning if we came through
390      * another path. So just zero them here.
391      */
392 
393     regs->ksp = 0;
394     regs->kpc = 0;
395     regs->orig_r28 = 0;
396 }
397 
398 
399 /*
400  * This routine handles various exception codes.  It determines the address,
401  * and the problem, and then passes it off to one of the appropriate
402  * routines.
403  */
parisc_terminate(char * msg,struct pt_regs * regs,int code,unsigned long offset)404 void parisc_terminate(char *msg, struct pt_regs *regs, int code, unsigned long offset)
405 {
406 	static spinlock_t terminate_lock = SPIN_LOCK_UNLOCKED;
407 
408 	set_eiem(0);
409 	__cli();
410 	spin_lock(&terminate_lock);
411 
412 	/* unlock the pdc lock if necessary */
413 	pdc_emergency_unlock();
414 
415 	/* restart pdc console if necessary */
416 	if (!console_drivers)
417 		pdc_console_restart();
418 
419 
420 	/* Not all switch paths will gutter the processor... */
421 	switch(code){
422 
423 	case 1:
424 		transfer_pim_to_trap_frame(regs);
425 		break;
426 
427 	default:
428 		/* Fall through */
429 		break;
430 	}
431 
432 	show_stack((unsigned long *)regs->gr[30]);
433 
434 	printk("\n");
435 	printk(KERN_CRIT "%s: Code=%d regs=%p (Addr=" RFMT ")\n",
436 			msg, code, regs, offset);
437 	show_regs(regs);
438 
439 	spin_unlock(&terminate_lock);
440 
441 	/* put soft power button back under hardware control;
442 	 * if the user had pressed it once at any time, the
443 	 * system will shut down immediately right here. */
444 	pdc_soft_power_button(0);
445 
446 	/* Gutter the processor... */
447 	for(;;)
448 	    ;
449 }
450 
451 
handle_interruption(int code,struct pt_regs * regs)452 void handle_interruption(int code, struct pt_regs *regs)
453 {
454 	unsigned long fault_address = 0;
455 	unsigned long fault_space = 0;
456 	struct siginfo si;
457 
458 	switch(code) {
459 
460 	case  1:
461 		/* High-priority machine check (HPMC) */
462 		pdc_console_restart();  /* switch back to pdc if HPMC */
463 
464 		/* set up a new led state on systems shipped with a LED State panel */
465 		pdc_chassis_send_status(PDC_CHASSIS_DIRECT_HPMC);
466 
467 		parisc_terminate("High Priority Machine Check (HPMC)",
468 				regs, code, 0);
469 		/* NOT REACHED */
470 
471 	case  2:
472 		/* Power failure interrupt */
473 		printk(KERN_CRIT "Power failure interrupt !\n");
474 		return;
475 
476 	case  3:
477 		/* Recovery counter trap */
478 		regs->gr[0] &= ~PSW_R;
479 		if (regs->iasq[0])
480 			handle_gdb_break(regs, TRAP_TRACE);
481 		/* else this must be the start of a syscall - just let it run */
482 		return;
483 
484 	case  5:
485 		/* Low-priority machine check */
486 
487 		pdc_chassis_send_status(PDC_CHASSIS_DIRECT_LPMC);
488 
489 		flush_all_caches();
490 		cpu_lpmc(5, regs);
491 		return;
492 
493 	case  6:
494 		/* Instruction TLB miss fault/Instruction page fault */
495 		fault_address = regs->iaoq[0];
496 		fault_space   = regs->iasq[0];
497 		break;
498 
499 	case  8:
500 		/* Illegal instruction trap */
501 		die_if_kernel("Illegal instruction", regs, code);
502 		si.si_code = ILL_ILLOPC;
503 		goto give_sigill;
504 
505 	case  9:
506 		/* Break instruction trap */
507 		handle_break(regs->iir,regs);
508 		return;
509 
510 	case 10:
511 		/* Privileged operation trap */
512 		die_if_kernel("Privileged operation", regs, code);
513 		si.si_code = ILL_PRVOPC;
514 		goto give_sigill;
515 
516 	case 11:
517 		/* Privileged register trap */
518 		if ((regs->iir & 0xffdfffe0) == 0x034008a0) {
519 
520 			/* This is a MFCTL cr26/cr27 to gr instruction.
521 			 * PCXS traps on this, so we need to emulate it.
522 			 */
523 
524 			if (regs->iir & 0x00200000)
525 				regs->gr[regs->iir & 0x1f] = mfctl(27);
526 			else
527 				regs->gr[regs->iir & 0x1f] = mfctl(26);
528 
529 			regs->iaoq[0] = regs->iaoq[1];
530 			regs->iaoq[1] += 4;
531 			regs->iasq[0] = regs->iasq[1];
532 			return;
533 		}
534 
535 		die_if_kernel("Privileged register usage", regs, code);
536 		si.si_code = ILL_PRVREG;
537 		/* Fall thru */
538 	give_sigill:
539 		si.si_signo = SIGILL;
540 		si.si_errno = 0;
541 		si.si_addr = (void *) regs->iaoq[0];
542 		force_sig_info(SIGILL, &si, current);
543 		return;
544 
545 	case 12:
546 		/* Overflow Trap, let the userland signal handler do the cleanup */
547 		si.si_signo = SIGFPE;
548 		si.si_code = FPE_INTOVF;
549 		si.si_addr = (void *) regs->iaoq[0];
550 		force_sig_info(SIGFPE, &si, current);
551 		return;
552 
553 	case 13:
554 		/* Conditional Trap
555 		   The condition succees in an instruction which traps on condition  */
556 		si.si_signo = SIGFPE;
557 		/* Set to zero, and let the userspace app figure it out from
558 		   the insn pointed to by si_addr */
559 		si.si_code = 0;
560 		si.si_addr = (void *) regs->iaoq[0];
561 		force_sig_info(SIGFPE, &si, current);
562 		return;
563 
564 	case 14:
565 		/* Assist Exception Trap, i.e. floating point exception. */
566 		die_if_kernel("Floating point exception", regs, 0); /* quiet */
567 		handle_fpe(regs);
568 		return;
569 
570 	case 15:
571 		/* Data TLB miss fault/Data page fault */
572 		/* Fall thru */
573 	case 16:
574 		/* Non-access instruction TLB miss fault */
575 		/* The instruction TLB entry needed for the target address of the FIC
576 		   is absent, and hardware can't find it, so we get to cleanup */
577 		/* Fall thru */
578 	case 17:
579 		/* Non-access data TLB miss fault/Non-access data page fault */
580 		/* TODO: Still need to add slow path emulation code here */
581 		/* TODO: Understand what is meant by the TODO listed
582 		   above this one. (Carlos) */
583 		fault_address = regs->ior;
584 		fault_space = regs->isr;
585 		break;
586 
587 	case 18:
588 		/* PCXS only -- later cpu's split this into types 26,27 & 28 */
589 		/* Check for unaligned access */
590 		if (check_unaligned(regs)) {
591 			handle_unaligned(regs);
592 			return;
593 		}
594 		/* Fall Through */
595 	case 26:
596 		/* PCXL: Data memory access rights trap */
597 		fault_address = regs->ior;
598 		fault_space   = regs->isr;
599 		break;
600 
601 	case 19:
602 		/* Data memory break trap */
603 		regs->gr[0] |= PSW_X; /* So we can single-step over the trap */
604 		/* fall thru */
605 	case 21:
606 		/* Page reference trap */
607 		handle_gdb_break(regs, TRAP_HWBKPT);
608 		return;
609 
610 	case 25:
611 		/* Taken branch trap */
612 		regs->gr[0] &= ~PSW_T;
613 		if (regs->iasq[0])
614 			handle_gdb_break(regs, TRAP_BRANCH);
615 		/* else this must be the start of a syscall - just let it
616 		 * run.
617 		 */
618 		return;
619 
620 	case  7:
621 		/* Instruction access rights */
622 		/* PCXL: Instruction memory protection trap */
623 
624 		/*
625 		 * This could be caused by either: 1) a process attempting
626 		 * to execute within a vma that does not have execute
627 		 * permission, or 2) an access rights violation caused by a
628 		 * flush only translation set up by ptep_get_and_clear().
629 		 * So we check the vma permissions to differentiate the two.
630 		 * If the vma indicates we have execute permission, then
631 		 * the cause is the latter one. In this case, we need to
632 		 * call do_page_fault() to fix the problem.
633 		 */
634 
635 		if (user_mode(regs)) {
636 			struct vm_area_struct *vma;
637 
638 			down_read(&current->mm->mmap_sem);
639 			vma = find_vma(current->mm,regs->iaoq[0]);
640 			if (vma && (regs->iaoq[0] >= vma->vm_start)
641 				&& (vma->vm_flags & VM_EXEC)) {
642 
643 				fault_address = regs->iaoq[0];
644 				fault_space = regs->iasq[0];
645 
646 				up_read(&current->mm->mmap_sem);
647 				break; /* call do_page_fault() */
648 			}
649 			up_read(&current->mm->mmap_sem);
650 		}
651 		/* Fall Through */
652 	case 27:
653 		/* Data memory protection ID trap */
654 		die_if_kernel("Protection id trap", regs, code);
655 		si.si_code = SEGV_MAPERR;
656 		si.si_signo = SIGSEGV;
657 		si.si_errno = 0;
658 		if (code == 7)
659 		    si.si_addr = (void *) regs->iaoq[0];
660 		else
661 		    si.si_addr = (void *) regs->ior;
662 		force_sig_info(SIGSEGV, &si, current);
663 		return;
664 
665 	case 28:
666 		/* Unaligned data reference trap */
667 		handle_unaligned(regs);
668 		return;
669 
670 	default:
671 		if (user_mode(regs)) {
672 #ifdef PRINT_USER_FAULTS
673 			printk(KERN_DEBUG "\nhandle_interruption() pid=%d command='%s'\n",
674 			    current->pid, current->comm);
675 			show_regs(regs);
676 #endif
677 			/* SIGBUS, for lack of a better one. */
678 			si.si_signo = SIGBUS;
679 			si.si_code = BUS_OBJERR;
680 			si.si_errno = 0;
681 			si.si_addr = (void *) regs->ior;
682 			force_sig_info(SIGBUS, &si, current);
683 			return;
684 		}
685 
686 		pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC);
687 
688 		parisc_terminate("Unexpected interruption", regs, code, 0);
689 		/* NOT REACHED */
690 	}
691 
692 	if (user_mode(regs)) {
693 	    if (fault_space != regs->sr[7]) {
694 #ifdef PRINT_USER_FAULTS
695 		if (fault_space == 0)
696 			printk(KERN_DEBUG "User Fault on Kernel Space ");
697 		else
698 			printk(KERN_DEBUG "User Fault (long pointer) ");
699 		printk("pid=%d command='%s'\n", current->pid, current->comm);
700 		show_regs(regs);
701 #endif
702 		si.si_signo = SIGSEGV;
703 		si.si_errno = 0;
704 		si.si_code = SEGV_MAPERR;
705 		si.si_addr = (void *) regs->ior;
706 		force_sig_info(SIGSEGV, &si, current);
707 		return;
708 	    }
709 	}
710 	else {
711 
712 	    /*
713 	     * The kernel should never fault on its own address space.
714 	     */
715 
716 	    if (fault_space == 0) {
717 		pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC);
718 		parisc_terminate("Kernel Fault", regs, code, fault_address);
719 		/** NOT REACHED **/
720 	    }
721 	}
722 
723 	local_irq_enable();
724 	do_page_fault(regs, code, fault_address);
725 }
726 
727 
728 
check_ivt(void * iva)729 int __init check_ivt(void *iva)
730 {
731 	int i;
732 	u32 check = 0;
733 	u32 *ivap;
734 	u32 *hpmcp;
735 	u32 length;
736 	extern void os_hpmc(void);
737 	extern void os_hpmc_end(void);
738 
739 	if (strcmp((char *)iva, "cows can fly"))
740 		return -1;
741 
742 	ivap = (u32 *)iva;
743 
744 	for (i = 0; i < 8; i++)
745 	    *ivap++ = 0;
746 
747 	/* Compute Checksum for HPMC handler */
748 
749 	length = (u32)((unsigned long)os_hpmc_end - (unsigned long)os_hpmc);
750 	ivap[7] = length;
751 
752 	hpmcp = (u32 *)os_hpmc;
753 
754 	for (i=0; i<length/4; i++)
755 	    check += *hpmcp++;
756 
757 	for (i=0; i<8; i++)
758 	    check += ivap[i];
759 
760 	ivap[5] = -check;
761 
762 	return 0;
763 }
764 
765 #ifndef __LP64__
766 extern const void fault_vector_11;
767 #endif
768 extern const void fault_vector_20;
769 
trap_init(void)770 void __init trap_init(void)
771 {
772 	void *iva;
773 
774 	if (boot_cpu_data.cpu_type >= pcxu)
775 		iva = (void *) &fault_vector_20;
776 	else
777 #ifdef __LP64__
778 		panic("Can't boot 64-bit OS on PA1.1 processor!");
779 #else
780 		iva = (void *) &fault_vector_11;
781 #endif
782 
783 	if (check_ivt(iva))
784 		panic("IVT invalid");
785 }
786