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#include <linux/kfence.h>
34
35#include <asm/assembly.h>
36#include <asm/io.h>
37#include <asm/irq.h>
38#include <asm/traps.h>
39#include <asm/unaligned.h>
40#include <linux/atomic.h>
41#include <asm/smp.h>
42#include <asm/pdc.h>
43#include <asm/pdc_chassis.h>
44#include <asm/unwind.h>
45#include <asm/tlbflush.h>
46#include <asm/cacheflush.h>
47#include <linux/kgdb.h>
48#include <linux/kprobes.h>
49
50#if defined(CONFIG_LIGHTWEIGHT_SPINLOCK_CHECK)
51#include <asm/spinlock.h>
52#endif
53
54#include "../math-emu/math-emu.h"	/* for handle_fpe() */
55
56static void parisc_show_stack(struct task_struct *task,
57	struct pt_regs *regs, const char *loglvl);
58
59static int printbinary(char *buf, unsigned long x, int nbits)
60{
61	unsigned long mask = 1UL << (nbits - 1);
62	while (mask != 0) {
63		*buf++ = (mask & x ? '1' : '0');
64		mask >>= 1;
65	}
66	*buf = '\0';
67
68	return nbits;
69}
70
71#ifdef CONFIG_64BIT
72#define RFMT "%016lx"
73#else
74#define RFMT "%08lx"
75#endif
76#define FFMT "%016llx"	/* fpregs are 64-bit always */
77
78#define PRINTREGS(lvl,r,f,fmt,x)	\
79	printk("%s%s%02d-%02d  " fmt " " fmt " " fmt " " fmt "\n",	\
80		lvl, f, (x), (x+3), (r)[(x)+0], (r)[(x)+1],		\
81		(r)[(x)+2], (r)[(x)+3])
82
83static void print_gr(const char *level, struct pt_regs *regs)
84{
85	int i;
86	char buf[64];
87
88	printk("%s\n", level);
89	printk("%s     YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI\n", level);
90	printbinary(buf, regs->gr[0], 32);
91	printk("%sPSW: %s %s\n", level, buf, print_tainted());
92
93	for (i = 0; i < 32; i += 4)
94		PRINTREGS(level, regs->gr, "r", RFMT, i);
95}
96
97static void print_fr(const char *level, struct pt_regs *regs)
98{
99	int i;
100	char buf[64];
101	struct { u32 sw[2]; } s;
102
103	/* FR are 64bit everywhere. Need to use asm to get the content
104	 * of fpsr/fper1, and we assume that we won't have a FP Identify
105	 * in our way, otherwise we're screwed.
106	 * The fldd is used to restore the T-bit if there was one, as the
107	 * store clears it anyway.
108	 * PA2.0 book says "thou shall not use fstw on FPSR/FPERs" - T-Bone */
109	asm volatile ("fstd %%fr0,0(%1)	\n\t"
110		      "fldd 0(%1),%%fr0	\n\t"
111		      : "=m" (s) : "r" (&s) : "r0");
112
113	printk("%s\n", level);
114	printk("%s      VZOUICununcqcqcqcqcqcrmunTDVZOUI\n", level);
115	printbinary(buf, s.sw[0], 32);
116	printk("%sFPSR: %s\n", level, buf);
117	printk("%sFPER1: %08x\n", level, s.sw[1]);
118
119	/* here we'll print fr0 again, tho it'll be meaningless */
120	for (i = 0; i < 32; i += 4)
121		PRINTREGS(level, regs->fr, "fr", FFMT, i);
122}
123
124void show_regs(struct pt_regs *regs)
125{
126	int i, user;
127	const char *level;
128	unsigned long cr30, cr31;
129
130	user = user_mode(regs);
131	level = user ? KERN_DEBUG : KERN_CRIT;
132
133	show_regs_print_info(level);
134
135	print_gr(level, regs);
136
137	for (i = 0; i < 8; i += 4)
138		PRINTREGS(level, regs->sr, "sr", RFMT, i);
139
140	if (user)
141		print_fr(level, regs);
142
143	cr30 = mfctl(30);
144	cr31 = mfctl(31);
145	printk("%s\n", level);
146	printk("%sIASQ: " RFMT " " RFMT " IAOQ: " RFMT " " RFMT "\n",
147	       level, regs->iasq[0], regs->iasq[1], regs->iaoq[0], regs->iaoq[1]);
148	printk("%s IIR: %08lx    ISR: " RFMT "  IOR: " RFMT "\n",
149	       level, regs->iir, regs->isr, regs->ior);
150	printk("%s CPU: %8d   CR30: " RFMT " CR31: " RFMT "\n",
151	       level, task_cpu(current), cr30, cr31);
152	printk("%s ORIG_R28: " RFMT "\n", level, regs->orig_r28);
153
154	if (user) {
155		printk("%s IAOQ[0]: " RFMT "\n", level, regs->iaoq[0]);
156		printk("%s IAOQ[1]: " RFMT "\n", level, regs->iaoq[1]);
157		printk("%s RP(r2): " RFMT "\n", level, regs->gr[2]);
158	} else {
159		printk("%s IAOQ[0]: %pS\n", level, (void *) regs->iaoq[0]);
160		printk("%s IAOQ[1]: %pS\n", level, (void *) regs->iaoq[1]);
161		printk("%s RP(r2): %pS\n", level, (void *) regs->gr[2]);
162
163		parisc_show_stack(current, regs, KERN_DEFAULT);
164	}
165}
166
167static DEFINE_RATELIMIT_STATE(_hppa_rs,
168	DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST);
169
170#define parisc_printk_ratelimited(critical, regs, fmt, ...)	{	      \
171	if ((critical || show_unhandled_signals) && __ratelimit(&_hppa_rs)) { \
172		printk(fmt, ##__VA_ARGS__);				      \
173		show_regs(regs);					      \
174	}								      \
175}
176
177
178static void do_show_stack(struct unwind_frame_info *info, const char *loglvl)
179{
180	int i = 1;
181
182	printk("%sBacktrace:\n", loglvl);
183	while (i <= MAX_UNWIND_ENTRIES) {
184		if (unwind_once(info) < 0 || info->ip == 0)
185			break;
186
187		if (__kernel_text_address(info->ip)) {
188			printk("%s [<" RFMT ">] %pS\n",
189				loglvl, info->ip, (void *) info->ip);
190			i++;
191		}
192	}
193	printk("%s\n", loglvl);
194}
195
196static void parisc_show_stack(struct task_struct *task,
197	struct pt_regs *regs, const char *loglvl)
198{
199	struct unwind_frame_info info;
200
201	unwind_frame_init_task(&info, task, regs);
202
203	do_show_stack(&info, loglvl);
204}
205
206void show_stack(struct task_struct *t, unsigned long *sp, const char *loglvl)
207{
208	parisc_show_stack(t, NULL, loglvl);
209}
210
211int is_valid_bugaddr(unsigned long iaoq)
212{
213	return 1;
214}
215
216void die_if_kernel(char *str, struct pt_regs *regs, long err)
217{
218	if (user_mode(regs)) {
219		if (err == 0)
220			return; /* STFU */
221
222		parisc_printk_ratelimited(1, regs,
223			KERN_CRIT "%s (pid %d): %s (code %ld) at " RFMT "\n",
224			current->comm, task_pid_nr(current), str, err, regs->iaoq[0]);
225
226		return;
227	}
228
229	bust_spinlocks(1);
230
231	oops_enter();
232
233	/* Amuse the user in a SPARC fashion */
234	if (err) printk(KERN_CRIT
235			"      _______________________________ \n"
236			"     < Your System ate a SPARC! Gah! >\n"
237			"      ------------------------------- \n"
238			"             \\   ^__^\n"
239			"                 (__)\\       )\\/\\\n"
240			"                  U  ||----w |\n"
241			"                     ||     ||\n");
242
243	/* unlock the pdc lock if necessary */
244	pdc_emergency_unlock();
245
246	if (err)
247		printk(KERN_CRIT "%s (pid %d): %s (code %ld)\n",
248			current->comm, task_pid_nr(current), str, err);
249
250	/* Wot's wrong wif bein' racy? */
251	if (current->thread.flags & PARISC_KERNEL_DEATH) {
252		printk(KERN_CRIT "%s() recursion detected.\n", __func__);
253		local_irq_enable();
254		while (1);
255	}
256	current->thread.flags |= PARISC_KERNEL_DEATH;
257
258	show_regs(regs);
259	dump_stack();
260	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
261
262	if (in_interrupt())
263		panic("Fatal exception in interrupt");
264
265	if (panic_on_oops)
266		panic("Fatal exception");
267
268	oops_exit();
269	make_task_dead(SIGSEGV);
270}
271
272/* gdb uses break 4,8 */
273#define GDB_BREAK_INSN 0x10004
274static void handle_gdb_break(struct pt_regs *regs, int wot)
275{
276	force_sig_fault(SIGTRAP, wot,
277			(void __user *) (regs->iaoq[0] & ~3));
278}
279
280static void handle_break(struct pt_regs *regs)
281{
282	unsigned iir = regs->iir;
283
284	if (unlikely(iir == PARISC_BUG_BREAK_INSN && !user_mode(regs))) {
285		/* check if a BUG() or WARN() trapped here.  */
286		enum bug_trap_type tt;
287		tt = report_bug(regs->iaoq[0] & ~3, regs);
288		if (tt == BUG_TRAP_TYPE_WARN) {
289			regs->iaoq[0] += 4;
290			regs->iaoq[1] += 4;
291			return; /* return to next instruction when WARN_ON().  */
292		}
293		die_if_kernel("Unknown kernel breakpoint", regs,
294			(tt == BUG_TRAP_TYPE_NONE) ? 9 : 0);
295	}
296
297#ifdef CONFIG_KPROBES
298	if (unlikely(iir == PARISC_KPROBES_BREAK_INSN && !user_mode(regs))) {
299		parisc_kprobe_break_handler(regs);
300		return;
301	}
302	if (unlikely(iir == PARISC_KPROBES_BREAK_INSN2 && !user_mode(regs))) {
303		parisc_kprobe_ss_handler(regs);
304		return;
305	}
306#endif
307
308#ifdef CONFIG_KGDB
309	if (unlikely((iir == PARISC_KGDB_COMPILED_BREAK_INSN ||
310		iir == PARISC_KGDB_BREAK_INSN)) && !user_mode(regs)) {
311		kgdb_handle_exception(9, SIGTRAP, 0, regs);
312		return;
313	}
314#endif
315
316#ifdef CONFIG_LIGHTWEIGHT_SPINLOCK_CHECK
317        if ((iir == SPINLOCK_BREAK_INSN) && !user_mode(regs)) {
318		die_if_kernel("Spinlock was trashed", regs, 1);
319	}
320#endif
321
322	if (unlikely(iir != GDB_BREAK_INSN))
323		parisc_printk_ratelimited(0, regs,
324			KERN_DEBUG "break %d,%d: pid=%d command='%s'\n",
325			iir & 31, (iir>>13) & ((1<<13)-1),
326			task_pid_nr(current), current->comm);
327
328	/* send standard GDB signal */
329	handle_gdb_break(regs, TRAP_BRKPT);
330}
331
332static void default_trap(int code, struct pt_regs *regs)
333{
334	printk(KERN_ERR "Trap %d on CPU %d\n", code, smp_processor_id());
335	show_regs(regs);
336}
337
338static void transfer_pim_to_trap_frame(struct pt_regs *regs)
339{
340    register int i;
341    extern unsigned int hpmc_pim_data[];
342    struct pdc_hpmc_pim_11 *pim_narrow;
343    struct pdc_hpmc_pim_20 *pim_wide;
344
345    if (boot_cpu_data.cpu_type >= pcxu) {
346
347	pim_wide = (struct pdc_hpmc_pim_20 *)hpmc_pim_data;
348
349	/*
350	 * Note: The following code will probably generate a
351	 * bunch of truncation error warnings from the compiler.
352	 * Could be handled with an ifdef, but perhaps there
353	 * is a better way.
354	 */
355
356	regs->gr[0] = pim_wide->cr[22];
357
358	for (i = 1; i < 32; i++)
359	    regs->gr[i] = pim_wide->gr[i];
360
361	for (i = 0; i < 32; i++)
362	    regs->fr[i] = pim_wide->fr[i];
363
364	for (i = 0; i < 8; i++)
365	    regs->sr[i] = pim_wide->sr[i];
366
367	regs->iasq[0] = pim_wide->cr[17];
368	regs->iasq[1] = pim_wide->iasq_back;
369	regs->iaoq[0] = pim_wide->cr[18];
370	regs->iaoq[1] = pim_wide->iaoq_back;
371
372	regs->sar  = pim_wide->cr[11];
373	regs->iir  = pim_wide->cr[19];
374	regs->isr  = pim_wide->cr[20];
375	regs->ior  = pim_wide->cr[21];
376    }
377    else {
378	pim_narrow = (struct pdc_hpmc_pim_11 *)hpmc_pim_data;
379
380	regs->gr[0] = pim_narrow->cr[22];
381
382	for (i = 1; i < 32; i++)
383	    regs->gr[i] = pim_narrow->gr[i];
384
385	for (i = 0; i < 32; i++)
386	    regs->fr[i] = pim_narrow->fr[i];
387
388	for (i = 0; i < 8; i++)
389	    regs->sr[i] = pim_narrow->sr[i];
390
391	regs->iasq[0] = pim_narrow->cr[17];
392	regs->iasq[1] = pim_narrow->iasq_back;
393	regs->iaoq[0] = pim_narrow->cr[18];
394	regs->iaoq[1] = pim_narrow->iaoq_back;
395
396	regs->sar  = pim_narrow->cr[11];
397	regs->iir  = pim_narrow->cr[19];
398	regs->isr  = pim_narrow->cr[20];
399	regs->ior  = pim_narrow->cr[21];
400    }
401
402    /*
403     * The following fields only have meaning if we came through
404     * another path. So just zero them here.
405     */
406
407    regs->ksp = 0;
408    regs->kpc = 0;
409    regs->orig_r28 = 0;
410}
411
412
413/*
414 * This routine is called as a last resort when everything else
415 * has gone clearly wrong. We get called for faults in kernel space,
416 * and HPMC's.
417 */
418void parisc_terminate(char *msg, struct pt_regs *regs, int code, unsigned long offset)
419{
420	static DEFINE_SPINLOCK(terminate_lock);
421
422	(void)notify_die(DIE_OOPS, msg, regs, 0, code, SIGTRAP);
423	bust_spinlocks(1);
424
425	set_eiem(0);
426	local_irq_disable();
427	spin_lock(&terminate_lock);
428
429	/* unlock the pdc lock if necessary */
430	pdc_emergency_unlock();
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 other 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 (!irqs_disabled_flags(regs->gr[0]))
482	    local_irq_enable();
483
484	/* Security check:
485	 * If the priority level is still user, and the
486	 * faulting space is not equal to the active space
487	 * then the user is attempting something in a space
488	 * that does not belong to them. Kill the process.
489	 *
490	 * This is normally the situation when the user
491	 * attempts to jump into the kernel space at the
492	 * wrong offset, be it at the gateway page or a
493	 * random location.
494	 *
495	 * We cannot normally signal the process because it
496	 * could *be* on the gateway page, and processes
497	 * executing on the gateway page can't have signals
498	 * delivered.
499	 *
500	 * We merely readjust the address into the users
501	 * space, at a destination address of zero, and
502	 * allow processing to continue.
503	 */
504	if (((unsigned long)regs->iaoq[0] & 3) &&
505	    ((unsigned long)regs->iasq[0] != (unsigned long)regs->sr[7])) {
506		/* Kill the user process later */
507		regs->iaoq[0] = 0 | 3;
508		regs->iaoq[1] = regs->iaoq[0] + 4;
509		regs->iasq[0] = regs->iasq[1] = regs->sr[7];
510		regs->gr[0] &= ~PSW_B;
511		return;
512	}
513
514#if 0
515	printk(KERN_CRIT "Interruption # %d\n", code);
516#endif
517
518	switch(code) {
519
520	case  1:
521		/* High-priority machine check (HPMC) */
522
523		/* set up a new led state on systems shipped with a LED State panel */
524		pdc_chassis_send_status(PDC_CHASSIS_DIRECT_HPMC);
525
526		parisc_terminate("High Priority Machine Check (HPMC)",
527				regs, code, 0);
528		/* NOT REACHED */
529
530	case  2:
531		/* Power failure interrupt */
532		printk(KERN_CRIT "Power failure interrupt !\n");
533		return;
534
535	case  3:
536		/* Recovery counter trap */
537		regs->gr[0] &= ~PSW_R;
538
539#ifdef CONFIG_KGDB
540		if (kgdb_single_step) {
541			kgdb_handle_exception(0, SIGTRAP, 0, regs);
542			return;
543		}
544#endif
545
546		if (user_space(regs))
547			handle_gdb_break(regs, TRAP_TRACE);
548		/* else this must be the start of a syscall - just let it run */
549		return;
550
551	case  5:
552		/* Low-priority machine check */
553		pdc_chassis_send_status(PDC_CHASSIS_DIRECT_LPMC);
554
555		flush_cache_all();
556		flush_tlb_all();
557		default_trap(code, regs);
558		return;
559
560	case  PARISC_ITLB_TRAP:
561		/* Instruction TLB miss fault/Instruction page fault */
562		fault_address = regs->iaoq[0];
563		fault_space   = regs->iasq[0];
564		break;
565
566	case  8:
567		/* Illegal instruction trap */
568		die_if_kernel("Illegal instruction", regs, code);
569		si_code = ILL_ILLOPC;
570		goto give_sigill;
571
572	case  9:
573		/* Break instruction trap */
574		handle_break(regs);
575		return;
576
577	case 10:
578		/* Privileged operation trap */
579		die_if_kernel("Privileged operation", regs, code);
580		si_code = ILL_PRVOPC;
581		goto give_sigill;
582
583	case 11:
584		/* Privileged register trap */
585		if ((regs->iir & 0xffdfffe0) == 0x034008a0) {
586
587			/* This is a MFCTL cr26/cr27 to gr instruction.
588			 * PCXS traps on this, so we need to emulate it.
589			 */
590
591			if (regs->iir & 0x00200000)
592				regs->gr[regs->iir & 0x1f] = mfctl(27);
593			else
594				regs->gr[regs->iir & 0x1f] = mfctl(26);
595
596			regs->iaoq[0] = regs->iaoq[1];
597			regs->iaoq[1] += 4;
598			regs->iasq[0] = regs->iasq[1];
599			return;
600		}
601
602		die_if_kernel("Privileged register usage", regs, code);
603		si_code = ILL_PRVREG;
604	give_sigill:
605		force_sig_fault(SIGILL, si_code,
606				(void __user *) regs->iaoq[0]);
607		return;
608
609	case 12:
610		/* Overflow Trap, let the userland signal handler do the cleanup */
611		force_sig_fault(SIGFPE, FPE_INTOVF,
612				(void __user *) regs->iaoq[0]);
613		return;
614
615	case 13:
616		/* Conditional Trap
617		   The condition succeeds in an instruction which traps
618		   on condition  */
619		if(user_mode(regs)){
620			/* Let userspace app figure it out from the insn pointed
621			 * to by si_addr.
622			 */
623			force_sig_fault(SIGFPE, FPE_CONDTRAP,
624					(void __user *) regs->iaoq[0]);
625			return;
626		}
627		/* The kernel doesn't want to handle condition codes */
628		break;
629
630	case 14:
631		/* Assist Exception Trap, i.e. floating point exception. */
632		die_if_kernel("Floating point exception", regs, 0); /* quiet */
633		__inc_irq_stat(irq_fpassist_count);
634		handle_fpe(regs);
635		return;
636
637	case 15:
638		/* Data TLB miss fault/Data page fault */
639		fallthrough;
640	case 16:
641		/* Non-access instruction TLB miss fault */
642		/* The instruction TLB entry needed for the target address of the FIC
643		   is absent, and hardware can't find it, so we get to cleanup */
644		fallthrough;
645	case 17:
646		/* Non-access data TLB miss fault/Non-access data page fault */
647		/* FIXME:
648			 Still need to add slow path emulation code here!
649			 If the insn used a non-shadow register, then the tlb
650			 handlers could not have their side-effect (e.g. probe
651			 writing to a target register) emulated since rfir would
652			 erase the changes to said register. Instead we have to
653			 setup everything, call this function we are in, and emulate
654			 by hand. Technically we need to emulate:
655			 fdc,fdce,pdc,"fic,4f",prober,probeir,probew, probeiw
656		*/
657		if (code == 17 && handle_nadtlb_fault(regs))
658			return;
659		fault_address = regs->ior;
660		fault_space = regs->isr;
661		break;
662
663	case 18:
664		/* PCXS only -- later cpu's split this into types 26,27 & 28 */
665		/* Check for unaligned access */
666		if (check_unaligned(regs)) {
667			handle_unaligned(regs);
668			return;
669		}
670		fallthrough;
671	case 26:
672		/* PCXL: Data memory access rights trap */
673		fault_address = regs->ior;
674		fault_space   = regs->isr;
675		break;
676
677	case 19:
678		/* Data memory break trap */
679		regs->gr[0] |= PSW_X; /* So we can single-step over the trap */
680		fallthrough;
681	case 21:
682		/* Page reference trap */
683		handle_gdb_break(regs, TRAP_HWBKPT);
684		return;
685
686	case 25:
687		/* Taken branch trap */
688		regs->gr[0] &= ~PSW_T;
689		if (user_space(regs))
690			handle_gdb_break(regs, TRAP_BRANCH);
691		/* else this must be the start of a syscall - just let it
692		 * run.
693		 */
694		return;
695
696	case  7:
697		/* Instruction access rights */
698		/* PCXL: Instruction memory protection trap */
699
700		/*
701		 * This could be caused by either: 1) a process attempting
702		 * to execute within a vma that does not have execute
703		 * permission, or 2) an access rights violation caused by a
704		 * flush only translation set up by ptep_get_and_clear().
705		 * So we check the vma permissions to differentiate the two.
706		 * If the vma indicates we have execute permission, then
707		 * the cause is the latter one. In this case, we need to
708		 * call do_page_fault() to fix the problem.
709		 */
710
711		if (user_mode(regs)) {
712			struct vm_area_struct *vma;
713
714			mmap_read_lock(current->mm);
715			vma = find_vma(current->mm,regs->iaoq[0]);
716			if (vma && (regs->iaoq[0] >= vma->vm_start)
717				&& (vma->vm_flags & VM_EXEC)) {
718
719				fault_address = regs->iaoq[0];
720				fault_space = regs->iasq[0];
721
722				mmap_read_unlock(current->mm);
723				break; /* call do_page_fault() */
724			}
725			mmap_read_unlock(current->mm);
726		}
727		/* CPU could not fetch instruction, so clear stale IIR value. */
728		regs->iir = 0xbaadf00d;
729		fallthrough;
730	case 27:
731		/* Data memory protection ID trap */
732		if (code == 27 && !user_mode(regs) &&
733			fixup_exception(regs))
734			return;
735
736		die_if_kernel("Protection id trap", regs, code);
737		force_sig_fault(SIGSEGV, SEGV_MAPERR,
738				(code == 7)?
739				((void __user *) regs->iaoq[0]) :
740				((void __user *) regs->ior));
741		return;
742
743	case 28:
744		/* Unaligned data reference trap */
745		handle_unaligned(regs);
746		return;
747
748	default:
749		if (user_mode(regs)) {
750			parisc_printk_ratelimited(0, regs, KERN_DEBUG
751				"handle_interruption() pid=%d command='%s'\n",
752				task_pid_nr(current), current->comm);
753			/* SIGBUS, for lack of a better one. */
754			force_sig_fault(SIGBUS, BUS_OBJERR,
755					(void __user *)regs->ior);
756			return;
757		}
758		pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC);
759
760		parisc_terminate("Unexpected interruption", regs, code, 0);
761		/* NOT REACHED */
762	}
763
764	if (user_mode(regs)) {
765	    if ((fault_space >> SPACEID_SHIFT) != (regs->sr[7] >> SPACEID_SHIFT)) {
766		parisc_printk_ratelimited(0, regs, KERN_DEBUG
767				"User fault %d on space 0x%08lx, pid=%d command='%s'\n",
768				code, fault_space,
769				task_pid_nr(current), current->comm);
770		force_sig_fault(SIGSEGV, SEGV_MAPERR,
771				(void __user *)regs->ior);
772		return;
773	    }
774	}
775	else {
776
777	    /*
778	     * The kernel should never fault on its own address space,
779	     * unless pagefault_disable() was called before.
780	     */
781
782	    if (faulthandler_disabled() || fault_space == 0)
783	    {
784		/* Clean up and return if in exception table. */
785		if (fixup_exception(regs))
786			return;
787		/* Clean up and return if handled by kfence. */
788		if (kfence_handle_page_fault(fault_address,
789			parisc_acctyp(code, regs->iir) == VM_WRITE, regs))
790			return;
791		pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC);
792		parisc_terminate("Kernel Fault", regs, code, fault_address);
793	    }
794	}
795
796	do_page_fault(regs, code, fault_address);
797}
798
799
800static void __init initialize_ivt(const void *iva)
801{
802	extern const u32 os_hpmc[];
803
804	int i;
805	u32 check = 0;
806	u32 *ivap;
807	u32 instr;
808
809	if (strcmp((const char *)iva, "cows can fly"))
810		panic("IVT invalid");
811
812	ivap = (u32 *)iva;
813
814	for (i = 0; i < 8; i++)
815	    *ivap++ = 0;
816
817	/*
818	 * Use PDC_INSTR firmware function to get instruction that invokes
819	 * PDCE_CHECK in HPMC handler.  See programming note at page 1-31 of
820	 * the PA 1.1 Firmware Architecture document.
821	 */
822	if (pdc_instr(&instr) == PDC_OK)
823		ivap[0] = instr;
824
825	/*
826	 * Rules for the checksum of the HPMC handler:
827	 * 1. The IVA does not point to PDC/PDH space (ie: the OS has installed
828	 *    its own IVA).
829	 * 2. The word at IVA + 32 is nonzero.
830	 * 3. If Length (IVA + 60) is not zero, then Length (IVA + 60) and
831	 *    Address (IVA + 56) are word-aligned.
832	 * 4. The checksum of the 8 words starting at IVA + 32 plus the sum of
833	 *    the Length/4 words starting at Address is zero.
834	 */
835
836	/* Setup IVA and compute checksum for HPMC handler */
837	ivap[6] = (u32)__pa(os_hpmc);
838
839	for (i=0; i<8; i++)
840	    check += ivap[i];
841
842	ivap[5] = -check;
843	pr_debug("initialize_ivt: IVA[6] = 0x%08x\n", ivap[6]);
844}
845
846
847/* early_trap_init() is called before we set up kernel mappings and
848 * write-protect the kernel */
849void  __init early_trap_init(void)
850{
851	extern const void fault_vector_20;
852
853#ifndef CONFIG_64BIT
854	extern const void fault_vector_11;
855	initialize_ivt(&fault_vector_11);
856#endif
857
858	initialize_ivt(&fault_vector_20);
859}
860