1// SPDX-License-Identifier: GPL-2.0
2/*
3 *  linux/arch/parisc/traps.c
4 *
5 *  Copyright (C) 1991, 1992  Linus Torvalds
6 *  Copyright (C) 1999, 2000  Philipp Rumpf <prumpf@tux.org>
7 */
8
9/*
10 * 'Traps.c' handles hardware traps and faults after we have saved some
11 * state in 'asm.s'.
12 */
13
14#include <linux/sched.h>
15#include <linux/sched/debug.h>
16#include <linux/kernel.h>
17#include <linux/string.h>
18#include <linux/errno.h>
19#include <linux/ptrace.h>
20#include <linux/timer.h>
21#include <linux/delay.h>
22#include <linux/mm.h>
23#include <linux/module.h>
24#include <linux/smp.h>
25#include <linux/spinlock.h>
26#include <linux/init.h>
27#include <linux/interrupt.h>
28#include <linux/console.h>
29#include <linux/bug.h>
30#include <linux/ratelimit.h>
31#include <linux/uaccess.h>
32#include <linux/kdebug.h>
33
34#include <asm/assembly.h>
35#include <asm/io.h>
36#include <asm/irq.h>
37#include <asm/traps.h>
38#include <asm/unaligned.h>
39#include <linux/atomic.h>
40#include <asm/smp.h>
41#include <asm/pdc.h>
42#include <asm/pdc_chassis.h>
43#include <asm/unwind.h>
44#include <asm/tlbflush.h>
45#include <asm/cacheflush.h>
46#include <linux/kgdb.h>
47#include <linux/kprobes.h>
48
49#include "../math-emu/math-emu.h"	/* for handle_fpe() */
50
51static void parisc_show_stack(struct task_struct *task,
52	struct pt_regs *regs, const char *loglvl);
53
54static int printbinary(char *buf, unsigned long x, int nbits)
55{
56	unsigned long mask = 1UL << (nbits - 1);
57	while (mask != 0) {
58		*buf++ = (mask & x ? '1' : '0');
59		mask >>= 1;
60	}
61	*buf = '\0';
62
63	return nbits;
64}
65
66#ifdef CONFIG_64BIT
67#define RFMT "%016lx"
68#else
69#define RFMT "%08lx"
70#endif
71#define FFMT "%016llx"	/* fpregs are 64-bit always */
72
73#define PRINTREGS(lvl,r,f,fmt,x)	\
74	printk("%s%s%02d-%02d  " fmt " " fmt " " fmt " " fmt "\n",	\
75		lvl, f, (x), (x+3), (r)[(x)+0], (r)[(x)+1],		\
76		(r)[(x)+2], (r)[(x)+3])
77
78static void print_gr(const char *level, struct pt_regs *regs)
79{
80	int i;
81	char buf[64];
82
83	printk("%s\n", level);
84	printk("%s     YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI\n", level);
85	printbinary(buf, regs->gr[0], 32);
86	printk("%sPSW: %s %s\n", level, buf, print_tainted());
87
88	for (i = 0; i < 32; i += 4)
89		PRINTREGS(level, regs->gr, "r", RFMT, i);
90}
91
92static void print_fr(const char *level, struct pt_regs *regs)
93{
94	int i;
95	char buf[64];
96	struct { u32 sw[2]; } s;
97
98	/* FR are 64bit everywhere. Need to use asm to get the content
99	 * of fpsr/fper1, and we assume that we won't have a FP Identify
100	 * in our way, otherwise we're screwed.
101	 * The fldd is used to restore the T-bit if there was one, as the
102	 * store clears it anyway.
103	 * PA2.0 book says "thou shall not use fstw on FPSR/FPERs" - T-Bone */
104	asm volatile ("fstd %%fr0,0(%1)	\n\t"
105		      "fldd 0(%1),%%fr0	\n\t"
106		      : "=m" (s) : "r" (&s) : "r0");
107
108	printk("%s\n", level);
109	printk("%s      VZOUICununcqcqcqcqcqcrmunTDVZOUI\n", level);
110	printbinary(buf, s.sw[0], 32);
111	printk("%sFPSR: %s\n", level, buf);
112	printk("%sFPER1: %08x\n", level, s.sw[1]);
113
114	/* here we'll print fr0 again, tho it'll be meaningless */
115	for (i = 0; i < 32; i += 4)
116		PRINTREGS(level, regs->fr, "fr", FFMT, i);
117}
118
119void show_regs(struct pt_regs *regs)
120{
121	int i, user;
122	const char *level;
123	unsigned long cr30, cr31;
124
125	user = user_mode(regs);
126	level = user ? KERN_DEBUG : KERN_CRIT;
127
128	show_regs_print_info(level);
129
130	print_gr(level, regs);
131
132	for (i = 0; i < 8; i += 4)
133		PRINTREGS(level, regs->sr, "sr", RFMT, i);
134
135	if (user)
136		print_fr(level, regs);
137
138	cr30 = mfctl(30);
139	cr31 = mfctl(31);
140	printk("%s\n", level);
141	printk("%sIASQ: " RFMT " " RFMT " IAOQ: " RFMT " " RFMT "\n",
142	       level, regs->iasq[0], regs->iasq[1], regs->iaoq[0], regs->iaoq[1]);
143	printk("%s IIR: %08lx    ISR: " RFMT "  IOR: " RFMT "\n",
144	       level, regs->iir, regs->isr, regs->ior);
145	printk("%s CPU: %8d   CR30: " RFMT " CR31: " RFMT "\n",
146	       level, current_thread_info()->cpu, cr30, cr31);
147	printk("%s ORIG_R28: " RFMT "\n", level, regs->orig_r28);
148
149	if (user) {
150		printk("%s IAOQ[0]: " RFMT "\n", level, regs->iaoq[0]);
151		printk("%s IAOQ[1]: " RFMT "\n", level, regs->iaoq[1]);
152		printk("%s RP(r2): " RFMT "\n", level, regs->gr[2]);
153	} else {
154		printk("%s IAOQ[0]: %pS\n", level, (void *) regs->iaoq[0]);
155		printk("%s IAOQ[1]: %pS\n", level, (void *) regs->iaoq[1]);
156		printk("%s RP(r2): %pS\n", level, (void *) regs->gr[2]);
157
158		parisc_show_stack(current, regs, KERN_DEFAULT);
159	}
160}
161
162static DEFINE_RATELIMIT_STATE(_hppa_rs,
163	DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST);
164
165#define parisc_printk_ratelimited(critical, regs, fmt, ...)	{	      \
166	if ((critical || show_unhandled_signals) && __ratelimit(&_hppa_rs)) { \
167		printk(fmt, ##__VA_ARGS__);				      \
168		show_regs(regs);					      \
169	}								      \
170}
171
172
173static void do_show_stack(struct unwind_frame_info *info, const char *loglvl)
174{
175	int i = 1;
176
177	printk("%sBacktrace:\n", loglvl);
178	while (i <= MAX_UNWIND_ENTRIES) {
179		if (unwind_once(info) < 0 || info->ip == 0)
180			break;
181
182		if (__kernel_text_address(info->ip)) {
183			printk("%s [<" RFMT ">] %pS\n",
184				loglvl, info->ip, (void *) info->ip);
185			i++;
186		}
187	}
188	printk("%s\n", loglvl);
189}
190
191static void parisc_show_stack(struct task_struct *task,
192	struct pt_regs *regs, const char *loglvl)
193{
194	struct unwind_frame_info info;
195
196	unwind_frame_init_task(&info, task, regs);
197
198	do_show_stack(&info, loglvl);
199}
200
201void show_stack(struct task_struct *t, unsigned long *sp, const char *loglvl)
202{
203	parisc_show_stack(t, NULL, loglvl);
204}
205
206int is_valid_bugaddr(unsigned long iaoq)
207{
208	return 1;
209}
210
211void die_if_kernel(char *str, struct pt_regs *regs, long err)
212{
213	if (user_mode(regs)) {
214		if (err == 0)
215			return; /* STFU */
216
217		parisc_printk_ratelimited(1, regs,
218			KERN_CRIT "%s (pid %d): %s (code %ld) at " RFMT "\n",
219			current->comm, task_pid_nr(current), str, err, regs->iaoq[0]);
220
221		return;
222	}
223
224	bust_spinlocks(1);
225
226	oops_enter();
227
228	/* Amuse the user in a SPARC fashion */
229	if (err) printk(KERN_CRIT
230			"      _______________________________ \n"
231			"     < Your System ate a SPARC! Gah! >\n"
232			"      ------------------------------- \n"
233			"             \\   ^__^\n"
234			"                 (__)\\       )\\/\\\n"
235			"                  U  ||----w |\n"
236			"                     ||     ||\n");
237
238	/* unlock the pdc lock if necessary */
239	pdc_emergency_unlock();
240
241	/* maybe the kernel hasn't booted very far yet and hasn't been able
242	 * to initialize the serial or STI console. In that case we should
243	 * re-enable the pdc console, so that the user will be able to
244	 * identify the problem. */
245	if (!console_drivers)
246		pdc_console_restart();
247
248	if (err)
249		printk(KERN_CRIT "%s (pid %d): %s (code %ld)\n",
250			current->comm, task_pid_nr(current), str, err);
251
252	/* Wot's wrong wif bein' racy? */
253	if (current->thread.flags & PARISC_KERNEL_DEATH) {
254		printk(KERN_CRIT "%s() recursion detected.\n", __func__);
255		local_irq_enable();
256		while (1);
257	}
258	current->thread.flags |= PARISC_KERNEL_DEATH;
259
260	show_regs(regs);
261	dump_stack();
262	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
263
264	if (in_interrupt())
265		panic("Fatal exception in interrupt");
266
267	if (panic_on_oops)
268		panic("Fatal exception");
269
270	oops_exit();
271	make_task_dead(SIGSEGV);
272}
273
274/* gdb uses break 4,8 */
275#define GDB_BREAK_INSN 0x10004
276static void handle_gdb_break(struct pt_regs *regs, int wot)
277{
278	force_sig_fault(SIGTRAP, wot,
279			(void __user *) (regs->iaoq[0] & ~3));
280}
281
282static void handle_break(struct pt_regs *regs)
283{
284	unsigned iir = regs->iir;
285
286	if (unlikely(iir == PARISC_BUG_BREAK_INSN && !user_mode(regs))) {
287		/* check if a BUG() or WARN() trapped here.  */
288		enum bug_trap_type tt;
289		tt = report_bug(regs->iaoq[0] & ~3, regs);
290		if (tt == BUG_TRAP_TYPE_WARN) {
291			regs->iaoq[0] += 4;
292			regs->iaoq[1] += 4;
293			return; /* return to next instruction when WARN_ON().  */
294		}
295		die_if_kernel("Unknown kernel breakpoint", regs,
296			(tt == BUG_TRAP_TYPE_NONE) ? 9 : 0);
297	}
298
299#ifdef CONFIG_KPROBES
300	if (unlikely(iir == PARISC_KPROBES_BREAK_INSN)) {
301		parisc_kprobe_break_handler(regs);
302		return;
303	}
304
305#endif
306
307#ifdef CONFIG_KGDB
308	if (unlikely((iir == PARISC_KGDB_COMPILED_BREAK_INSN ||
309		iir == PARISC_KGDB_BREAK_INSN)) && !user_mode(regs)) {
310		kgdb_handle_exception(9, SIGTRAP, 0, regs);
311		return;
312	}
313#endif
314
315	if (unlikely(iir != GDB_BREAK_INSN))
316		parisc_printk_ratelimited(0, regs,
317			KERN_DEBUG "break %d,%d: pid=%d command='%s'\n",
318			iir & 31, (iir>>13) & ((1<<13)-1),
319			task_pid_nr(current), current->comm);
320
321	/* send standard GDB signal */
322	handle_gdb_break(regs, TRAP_BRKPT);
323}
324
325static void default_trap(int code, struct pt_regs *regs)
326{
327	printk(KERN_ERR "Trap %d on CPU %d\n", code, smp_processor_id());
328	show_regs(regs);
329}
330
331void (*cpu_lpmc) (int code, struct pt_regs *regs) __read_mostly = default_trap;
332
333
334void transfer_pim_to_trap_frame(struct pt_regs *regs)
335{
336    register int i;
337    extern unsigned int hpmc_pim_data[];
338    struct pdc_hpmc_pim_11 *pim_narrow;
339    struct pdc_hpmc_pim_20 *pim_wide;
340
341    if (boot_cpu_data.cpu_type >= pcxu) {
342
343	pim_wide = (struct pdc_hpmc_pim_20 *)hpmc_pim_data;
344
345	/*
346	 * Note: The following code will probably generate a
347	 * bunch of truncation error warnings from the compiler.
348	 * Could be handled with an ifdef, but perhaps there
349	 * is a better way.
350	 */
351
352	regs->gr[0] = pim_wide->cr[22];
353
354	for (i = 1; i < 32; i++)
355	    regs->gr[i] = pim_wide->gr[i];
356
357	for (i = 0; i < 32; i++)
358	    regs->fr[i] = pim_wide->fr[i];
359
360	for (i = 0; i < 8; i++)
361	    regs->sr[i] = pim_wide->sr[i];
362
363	regs->iasq[0] = pim_wide->cr[17];
364	regs->iasq[1] = pim_wide->iasq_back;
365	regs->iaoq[0] = pim_wide->cr[18];
366	regs->iaoq[1] = pim_wide->iaoq_back;
367
368	regs->sar  = pim_wide->cr[11];
369	regs->iir  = pim_wide->cr[19];
370	regs->isr  = pim_wide->cr[20];
371	regs->ior  = pim_wide->cr[21];
372    }
373    else {
374	pim_narrow = (struct pdc_hpmc_pim_11 *)hpmc_pim_data;
375
376	regs->gr[0] = pim_narrow->cr[22];
377
378	for (i = 1; i < 32; i++)
379	    regs->gr[i] = pim_narrow->gr[i];
380
381	for (i = 0; i < 32; i++)
382	    regs->fr[i] = pim_narrow->fr[i];
383
384	for (i = 0; i < 8; i++)
385	    regs->sr[i] = pim_narrow->sr[i];
386
387	regs->iasq[0] = pim_narrow->cr[17];
388	regs->iasq[1] = pim_narrow->iasq_back;
389	regs->iaoq[0] = pim_narrow->cr[18];
390	regs->iaoq[1] = pim_narrow->iaoq_back;
391
392	regs->sar  = pim_narrow->cr[11];
393	regs->iir  = pim_narrow->cr[19];
394	regs->isr  = pim_narrow->cr[20];
395	regs->ior  = pim_narrow->cr[21];
396    }
397
398    /*
399     * The following fields only have meaning if we came through
400     * another path. So just zero them here.
401     */
402
403    regs->ksp = 0;
404    regs->kpc = 0;
405    regs->orig_r28 = 0;
406}
407
408
409/*
410 * This routine is called as a last resort when everything else
411 * has gone clearly wrong. We get called for faults in kernel space,
412 * and HPMC's.
413 */
414void parisc_terminate(char *msg, struct pt_regs *regs, int code, unsigned long offset)
415{
416	static DEFINE_SPINLOCK(terminate_lock);
417
418	(void)notify_die(DIE_OOPS, msg, regs, 0, code, SIGTRAP);
419	bust_spinlocks(1);
420
421	set_eiem(0);
422	local_irq_disable();
423	spin_lock(&terminate_lock);
424
425	/* unlock the pdc lock if necessary */
426	pdc_emergency_unlock();
427
428	/* restart pdc console if necessary */
429	if (!console_drivers)
430		pdc_console_restart();
431
432	/* Not all paths will gutter the processor... */
433	switch(code){
434
435	case 1:
436		transfer_pim_to_trap_frame(regs);
437		break;
438
439	default:
440		break;
441
442	}
443
444	{
445		/* show_stack(NULL, (unsigned long *)regs->gr[30]); */
446		struct unwind_frame_info info;
447		unwind_frame_init(&info, current, regs);
448		do_show_stack(&info, KERN_CRIT);
449	}
450
451	printk("\n");
452	pr_crit("%s: Code=%d (%s) at addr " RFMT "\n",
453		msg, code, trap_name(code), offset);
454	show_regs(regs);
455
456	spin_unlock(&terminate_lock);
457
458	/* put soft power button back under hardware control;
459	 * if the user had pressed it once at any time, the
460	 * system will shut down immediately right here. */
461	pdc_soft_power_button(0);
462
463	/* Call kernel panic() so reboot timeouts work properly
464	 * FIXME: This function should be on the list of
465	 * panic notifiers, and we should call panic
466	 * directly from the location that we wish.
467	 * e.g. We should not call panic from
468	 * parisc_terminate, but rather the oter way around.
469	 * This hack works, prints the panic message twice,
470	 * and it enables reboot timers!
471	 */
472	panic(msg);
473}
474
475void notrace handle_interruption(int code, struct pt_regs *regs)
476{
477	unsigned long fault_address = 0;
478	unsigned long fault_space = 0;
479	int si_code;
480
481	if (code == 1)
482	    pdc_console_restart();  /* switch back to pdc if HPMC */
483	else
484	    local_irq_enable();
485
486	/* Security check:
487	 * If the priority level is still user, and the
488	 * faulting space is not equal to the active space
489	 * then the user is attempting something in a space
490	 * that does not belong to them. Kill the process.
491	 *
492	 * This is normally the situation when the user
493	 * attempts to jump into the kernel space at the
494	 * wrong offset, be it at the gateway page or a
495	 * random location.
496	 *
497	 * We cannot normally signal the process because it
498	 * could *be* on the gateway page, and processes
499	 * executing on the gateway page can't have signals
500	 * delivered.
501	 *
502	 * We merely readjust the address into the users
503	 * space, at a destination address of zero, and
504	 * allow processing to continue.
505	 */
506	if (((unsigned long)regs->iaoq[0] & 3) &&
507	    ((unsigned long)regs->iasq[0] != (unsigned long)regs->sr[7])) {
508		/* Kill the user process later */
509		regs->iaoq[0] = 0 | 3;
510		regs->iaoq[1] = regs->iaoq[0] + 4;
511		regs->iasq[0] = regs->iasq[1] = regs->sr[7];
512		regs->gr[0] &= ~PSW_B;
513		return;
514	}
515
516#if 0
517	printk(KERN_CRIT "Interruption # %d\n", code);
518#endif
519
520	switch(code) {
521
522	case  1:
523		/* High-priority machine check (HPMC) */
524
525		/* set up a new led state on systems shipped with a LED State panel */
526		pdc_chassis_send_status(PDC_CHASSIS_DIRECT_HPMC);
527
528		parisc_terminate("High Priority Machine Check (HPMC)",
529				regs, code, 0);
530		/* NOT REACHED */
531
532	case  2:
533		/* Power failure interrupt */
534		printk(KERN_CRIT "Power failure interrupt !\n");
535		return;
536
537	case  3:
538		/* Recovery counter trap */
539		regs->gr[0] &= ~PSW_R;
540
541#ifdef CONFIG_KPROBES
542		if (parisc_kprobe_ss_handler(regs))
543			return;
544#endif
545
546#ifdef CONFIG_KGDB
547		if (kgdb_single_step) {
548			kgdb_handle_exception(0, SIGTRAP, 0, regs);
549			return;
550		}
551#endif
552
553		if (user_space(regs))
554			handle_gdb_break(regs, TRAP_TRACE);
555		/* else this must be the start of a syscall - just let it run */
556		return;
557
558	case  5:
559		/* Low-priority machine check */
560		pdc_chassis_send_status(PDC_CHASSIS_DIRECT_LPMC);
561
562		flush_cache_all();
563		flush_tlb_all();
564		cpu_lpmc(5, regs);
565		return;
566
567	case  PARISC_ITLB_TRAP:
568		/* Instruction TLB miss fault/Instruction page fault */
569		fault_address = regs->iaoq[0];
570		fault_space   = regs->iasq[0];
571		break;
572
573	case  8:
574		/* Illegal instruction trap */
575		die_if_kernel("Illegal instruction", regs, code);
576		si_code = ILL_ILLOPC;
577		goto give_sigill;
578
579	case  9:
580		/* Break instruction trap */
581		handle_break(regs);
582		return;
583
584	case 10:
585		/* Privileged operation trap */
586		die_if_kernel("Privileged operation", regs, code);
587		si_code = ILL_PRVOPC;
588		goto give_sigill;
589
590	case 11:
591		/* Privileged register trap */
592		if ((regs->iir & 0xffdfffe0) == 0x034008a0) {
593
594			/* This is a MFCTL cr26/cr27 to gr instruction.
595			 * PCXS traps on this, so we need to emulate it.
596			 */
597
598			if (regs->iir & 0x00200000)
599				regs->gr[regs->iir & 0x1f] = mfctl(27);
600			else
601				regs->gr[regs->iir & 0x1f] = mfctl(26);
602
603			regs->iaoq[0] = regs->iaoq[1];
604			regs->iaoq[1] += 4;
605			regs->iasq[0] = regs->iasq[1];
606			return;
607		}
608
609		die_if_kernel("Privileged register usage", regs, code);
610		si_code = ILL_PRVREG;
611	give_sigill:
612		force_sig_fault(SIGILL, si_code,
613				(void __user *) regs->iaoq[0]);
614		return;
615
616	case 12:
617		/* Overflow Trap, let the userland signal handler do the cleanup */
618		force_sig_fault(SIGFPE, FPE_INTOVF,
619				(void __user *) regs->iaoq[0]);
620		return;
621
622	case 13:
623		/* Conditional Trap
624		   The condition succeeds in an instruction which traps
625		   on condition  */
626		if(user_mode(regs)){
627			/* Let userspace app figure it out from the insn pointed
628			 * to by si_addr.
629			 */
630			force_sig_fault(SIGFPE, FPE_CONDTRAP,
631					(void __user *) regs->iaoq[0]);
632			return;
633		}
634		/* The kernel doesn't want to handle condition codes */
635		break;
636
637	case 14:
638		/* Assist Exception Trap, i.e. floating point exception. */
639		die_if_kernel("Floating point exception", regs, 0); /* quiet */
640		__inc_irq_stat(irq_fpassist_count);
641		handle_fpe(regs);
642		return;
643
644	case 15:
645		/* Data TLB miss fault/Data page fault */
646		fallthrough;
647	case 16:
648		/* Non-access instruction TLB miss fault */
649		/* The instruction TLB entry needed for the target address of the FIC
650		   is absent, and hardware can't find it, so we get to cleanup */
651		fallthrough;
652	case 17:
653		/* Non-access data TLB miss fault/Non-access data page fault */
654		/* FIXME:
655			 Still need to add slow path emulation code here!
656			 If the insn used a non-shadow register, then the tlb
657			 handlers could not have their side-effect (e.g. probe
658			 writing to a target register) emulated since rfir would
659			 erase the changes to said register. Instead we have to
660			 setup everything, call this function we are in, and emulate
661			 by hand. Technically we need to emulate:
662			 fdc,fdce,pdc,"fic,4f",prober,probeir,probew, probeiw
663		*/
664		if (code == 17 && handle_nadtlb_fault(regs))
665			return;
666		fault_address = regs->ior;
667		fault_space = regs->isr;
668		break;
669
670	case 18:
671		/* PCXS only -- later cpu's split this into types 26,27 & 28 */
672		/* Check for unaligned access */
673		if (check_unaligned(regs)) {
674			handle_unaligned(regs);
675			return;
676		}
677		fallthrough;
678	case 26:
679		/* PCXL: Data memory access rights trap */
680		fault_address = regs->ior;
681		fault_space   = regs->isr;
682		break;
683
684	case 19:
685		/* Data memory break trap */
686		regs->gr[0] |= PSW_X; /* So we can single-step over the trap */
687		fallthrough;
688	case 21:
689		/* Page reference trap */
690		handle_gdb_break(regs, TRAP_HWBKPT);
691		return;
692
693	case 25:
694		/* Taken branch trap */
695		regs->gr[0] &= ~PSW_T;
696		if (user_space(regs))
697			handle_gdb_break(regs, TRAP_BRANCH);
698		/* else this must be the start of a syscall - just let it
699		 * run.
700		 */
701		return;
702
703	case  7:
704		/* Instruction access rights */
705		/* PCXL: Instruction memory protection trap */
706
707		/*
708		 * This could be caused by either: 1) a process attempting
709		 * to execute within a vma that does not have execute
710		 * permission, or 2) an access rights violation caused by a
711		 * flush only translation set up by ptep_get_and_clear().
712		 * So we check the vma permissions to differentiate the two.
713		 * If the vma indicates we have execute permission, then
714		 * the cause is the latter one. In this case, we need to
715		 * call do_page_fault() to fix the problem.
716		 */
717
718		if (user_mode(regs)) {
719			struct vm_area_struct *vma;
720
721			mmap_read_lock(current->mm);
722			vma = find_vma(current->mm,regs->iaoq[0]);
723			if (vma && (regs->iaoq[0] >= vma->vm_start)
724				&& (vma->vm_flags & VM_EXEC)) {
725
726				fault_address = regs->iaoq[0];
727				fault_space = regs->iasq[0];
728
729				mmap_read_unlock(current->mm);
730				break; /* call do_page_fault() */
731			}
732			mmap_read_unlock(current->mm);
733		}
734		/* CPU could not fetch instruction, so clear stale IIR value. */
735		regs->iir = 0xbaadf00d;
736		fallthrough;
737	case 27:
738		/* Data memory protection ID trap */
739		if (code == 27 && !user_mode(regs) &&
740			fixup_exception(regs))
741			return;
742
743		die_if_kernel("Protection id trap", regs, code);
744		force_sig_fault(SIGSEGV, SEGV_MAPERR,
745				(code == 7)?
746				((void __user *) regs->iaoq[0]) :
747				((void __user *) regs->ior));
748		return;
749
750	case 28:
751		/* Unaligned data reference trap */
752		handle_unaligned(regs);
753		return;
754
755	default:
756		if (user_mode(regs)) {
757			parisc_printk_ratelimited(0, regs, KERN_DEBUG
758				"handle_interruption() pid=%d command='%s'\n",
759				task_pid_nr(current), current->comm);
760			/* SIGBUS, for lack of a better one. */
761			force_sig_fault(SIGBUS, BUS_OBJERR,
762					(void __user *)regs->ior);
763			return;
764		}
765		pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC);
766
767		parisc_terminate("Unexpected interruption", regs, code, 0);
768		/* NOT REACHED */
769	}
770
771	if (user_mode(regs)) {
772	    if ((fault_space >> SPACEID_SHIFT) != (regs->sr[7] >> SPACEID_SHIFT)) {
773		parisc_printk_ratelimited(0, regs, KERN_DEBUG
774				"User fault %d on space 0x%08lx, pid=%d command='%s'\n",
775				code, fault_space,
776				task_pid_nr(current), current->comm);
777		force_sig_fault(SIGSEGV, SEGV_MAPERR,
778				(void __user *)regs->ior);
779		return;
780	    }
781	}
782	else {
783
784	    /*
785	     * The kernel should never fault on its own address space,
786	     * unless pagefault_disable() was called before.
787	     */
788
789	    if (faulthandler_disabled() || fault_space == 0)
790	    {
791		/* Clean up and return if in exception table. */
792		if (fixup_exception(regs))
793			return;
794		pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC);
795		parisc_terminate("Kernel Fault", regs, code, fault_address);
796	    }
797	}
798
799	do_page_fault(regs, code, fault_address);
800}
801
802
803void __init initialize_ivt(const void *iva)
804{
805	extern u32 os_hpmc_size;
806	extern const u32 os_hpmc[];
807
808	int i;
809	u32 check = 0;
810	u32 *ivap;
811	u32 *hpmcp;
812	u32 length, instr;
813
814	if (strcmp((const char *)iva, "cows can fly"))
815		panic("IVT invalid");
816
817	ivap = (u32 *)iva;
818
819	for (i = 0; i < 8; i++)
820	    *ivap++ = 0;
821
822	/*
823	 * Use PDC_INSTR firmware function to get instruction that invokes
824	 * PDCE_CHECK in HPMC handler.  See programming note at page 1-31 of
825	 * the PA 1.1 Firmware Architecture document.
826	 */
827	if (pdc_instr(&instr) == PDC_OK)
828		ivap[0] = instr;
829
830	/*
831	 * Rules for the checksum of the HPMC handler:
832	 * 1. The IVA does not point to PDC/PDH space (ie: the OS has installed
833	 *    its own IVA).
834	 * 2. The word at IVA + 32 is nonzero.
835	 * 3. If Length (IVA + 60) is not zero, then Length (IVA + 60) and
836	 *    Address (IVA + 56) are word-aligned.
837	 * 4. The checksum of the 8 words starting at IVA + 32 plus the sum of
838	 *    the Length/4 words starting at Address is zero.
839	 */
840
841	/* Setup IVA and compute checksum for HPMC handler */
842	ivap[6] = (u32)__pa(os_hpmc);
843	length = os_hpmc_size;
844	ivap[7] = length;
845
846	hpmcp = (u32 *)os_hpmc;
847
848	for (i=0; i<length/4; i++)
849	    check += *hpmcp++;
850
851	for (i=0; i<8; i++)
852	    check += ivap[i];
853
854	ivap[5] = -check;
855}
856
857
858/* early_trap_init() is called before we set up kernel mappings and
859 * write-protect the kernel */
860void  __init early_trap_init(void)
861{
862	extern const void fault_vector_20;
863
864#ifndef CONFIG_64BIT
865	extern const void fault_vector_11;
866	initialize_ivt(&fault_vector_11);
867#endif
868
869	initialize_ivt(&fault_vector_20);
870}
871
872void __init trap_init(void)
873{
874}
875