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/sched.h>
14 #include <linux/kernel.h>
15 #include <linux/string.h>
16 #include <linux/errno.h>
17 #include <linux/ptrace.h>
18 #include <linux/timer.h>
19 #include <linux/delay.h>
20 #include <linux/mm.h>
21 #include <linux/module.h>
22 #include <linux/smp.h>
23 #include <linux/spinlock.h>
24 #include <linux/init.h>
25 #include <linux/interrupt.h>
26 #include <linux/console.h>
27 #include <linux/bug.h>
28
29 #include <asm/assembly.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 <linux/atomic.h>
36 #include <asm/smp.h>
37 #include <asm/pdc.h>
38 #include <asm/pdc_chassis.h>
39 #include <asm/unwind.h>
40 #include <asm/tlbflush.h>
41 #include <asm/cacheflush.h>
42
43 #include "../math-emu/math-emu.h" /* for handle_fpe() */
44
45 #define PRINT_USER_FAULTS /* (turn this on if you want user faults to be */
46 /* dumped to the console via printk) */
47
48 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
49 DEFINE_SPINLOCK(pa_dbit_lock);
50 #endif
51
52 static void parisc_show_stack(struct task_struct *task, unsigned long *sp,
53 struct pt_regs *regs);
54
printbinary(char * buf,unsigned long x,int nbits)55 static int printbinary(char *buf, unsigned long x, int nbits)
56 {
57 unsigned long mask = 1UL << (nbits - 1);
58 while (mask != 0) {
59 *buf++ = (mask & x ? '1' : '0');
60 mask >>= 1;
61 }
62 *buf = '\0';
63
64 return nbits;
65 }
66
67 #ifdef CONFIG_64BIT
68 #define RFMT "%016lx"
69 #else
70 #define RFMT "%08lx"
71 #endif
72 #define FFMT "%016llx" /* fpregs are 64-bit always */
73
74 #define PRINTREGS(lvl,r,f,fmt,x) \
75 printk("%s%s%02d-%02d " fmt " " fmt " " fmt " " fmt "\n", \
76 lvl, f, (x), (x+3), (r)[(x)+0], (r)[(x)+1], \
77 (r)[(x)+2], (r)[(x)+3])
78
print_gr(char * level,struct pt_regs * regs)79 static void print_gr(char *level, struct pt_regs *regs)
80 {
81 int i;
82 char buf[64];
83
84 printk("%s\n", level);
85 printk("%s YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI\n", level);
86 printbinary(buf, regs->gr[0], 32);
87 printk("%sPSW: %s %s\n", level, buf, print_tainted());
88
89 for (i = 0; i < 32; i += 4)
90 PRINTREGS(level, regs->gr, "r", RFMT, i);
91 }
92
print_fr(char * level,struct pt_regs * regs)93 static void print_fr(char *level, struct pt_regs *regs)
94 {
95 int i;
96 char buf[64];
97 struct { u32 sw[2]; } s;
98
99 /* FR are 64bit everywhere. Need to use asm to get the content
100 * of fpsr/fper1, and we assume that we won't have a FP Identify
101 * in our way, otherwise we're screwed.
102 * The fldd is used to restore the T-bit if there was one, as the
103 * store clears it anyway.
104 * PA2.0 book says "thou shall not use fstw on FPSR/FPERs" - T-Bone */
105 asm volatile ("fstd %%fr0,0(%1) \n\t"
106 "fldd 0(%1),%%fr0 \n\t"
107 : "=m" (s) : "r" (&s) : "r0");
108
109 printk("%s\n", level);
110 printk("%s VZOUICununcqcqcqcqcqcrmunTDVZOUI\n", level);
111 printbinary(buf, s.sw[0], 32);
112 printk("%sFPSR: %s\n", level, buf);
113 printk("%sFPER1: %08x\n", level, s.sw[1]);
114
115 /* here we'll print fr0 again, tho it'll be meaningless */
116 for (i = 0; i < 32; i += 4)
117 PRINTREGS(level, regs->fr, "fr", FFMT, i);
118 }
119
show_regs(struct pt_regs * regs)120 void show_regs(struct pt_regs *regs)
121 {
122 int i, user;
123 char *level;
124 unsigned long cr30, cr31;
125
126 user = user_mode(regs);
127 level = user ? KERN_DEBUG : KERN_CRIT;
128
129 print_gr(level, regs);
130
131 for (i = 0; i < 8; i += 4)
132 PRINTREGS(level, regs->sr, "sr", RFMT, i);
133
134 if (user)
135 print_fr(level, regs);
136
137 cr30 = mfctl(30);
138 cr31 = mfctl(31);
139 printk("%s\n", level);
140 printk("%sIASQ: " RFMT " " RFMT " IAOQ: " RFMT " " RFMT "\n",
141 level, regs->iasq[0], regs->iasq[1], regs->iaoq[0], regs->iaoq[1]);
142 printk("%s IIR: %08lx ISR: " RFMT " IOR: " RFMT "\n",
143 level, regs->iir, regs->isr, regs->ior);
144 printk("%s CPU: %8d CR30: " RFMT " CR31: " RFMT "\n",
145 level, current_thread_info()->cpu, cr30, cr31);
146 printk("%s ORIG_R28: " RFMT "\n", level, regs->orig_r28);
147
148 if (user) {
149 printk("%s IAOQ[0]: " RFMT "\n", level, regs->iaoq[0]);
150 printk("%s IAOQ[1]: " RFMT "\n", level, regs->iaoq[1]);
151 printk("%s RP(r2): " RFMT "\n", level, regs->gr[2]);
152 } else {
153 printk("%s IAOQ[0]: %pS\n", level, (void *) regs->iaoq[0]);
154 printk("%s IAOQ[1]: %pS\n", level, (void *) regs->iaoq[1]);
155 printk("%s RP(r2): %pS\n", level, (void *) regs->gr[2]);
156
157 parisc_show_stack(current, NULL, regs);
158 }
159 }
160
161
dump_stack(void)162 void dump_stack(void)
163 {
164 show_stack(NULL, NULL);
165 }
166
167 EXPORT_SYMBOL(dump_stack);
168
do_show_stack(struct unwind_frame_info * info)169 static void do_show_stack(struct unwind_frame_info *info)
170 {
171 int i = 1;
172
173 printk(KERN_CRIT "Backtrace:\n");
174 while (i <= 16) {
175 if (unwind_once(info) < 0 || info->ip == 0)
176 break;
177
178 if (__kernel_text_address(info->ip)) {
179 printk(KERN_CRIT " [<" RFMT ">] %pS\n",
180 info->ip, (void *) info->ip);
181 i++;
182 }
183 }
184 printk(KERN_CRIT "\n");
185 }
186
parisc_show_stack(struct task_struct * task,unsigned long * sp,struct pt_regs * regs)187 static void parisc_show_stack(struct task_struct *task, unsigned long *sp,
188 struct pt_regs *regs)
189 {
190 struct unwind_frame_info info;
191 struct task_struct *t;
192
193 t = task ? task : current;
194 if (regs) {
195 unwind_frame_init(&info, t, regs);
196 goto show_stack;
197 }
198
199 if (t == current) {
200 unsigned long sp;
201
202 HERE:
203 asm volatile ("copy %%r30, %0" : "=r"(sp));
204 {
205 struct pt_regs r;
206
207 memset(&r, 0, sizeof(struct pt_regs));
208 r.iaoq[0] = (unsigned long)&&HERE;
209 r.gr[2] = (unsigned long)__builtin_return_address(0);
210 r.gr[30] = sp;
211
212 unwind_frame_init(&info, current, &r);
213 }
214 } else {
215 unwind_frame_init_from_blocked_task(&info, t);
216 }
217
218 show_stack:
219 do_show_stack(&info);
220 }
221
show_stack(struct task_struct * t,unsigned long * sp)222 void show_stack(struct task_struct *t, unsigned long *sp)
223 {
224 return parisc_show_stack(t, sp, NULL);
225 }
226
is_valid_bugaddr(unsigned long iaoq)227 int is_valid_bugaddr(unsigned long iaoq)
228 {
229 return 1;
230 }
231
die_if_kernel(char * str,struct pt_regs * regs,long err)232 void die_if_kernel(char *str, struct pt_regs *regs, long err)
233 {
234 if (user_mode(regs)) {
235 if (err == 0)
236 return; /* STFU */
237
238 printk(KERN_CRIT "%s (pid %d): %s (code %ld) at " RFMT "\n",
239 current->comm, task_pid_nr(current), str, err, regs->iaoq[0]);
240 #ifdef PRINT_USER_FAULTS
241 /* XXX for debugging only */
242 show_regs(regs);
243 #endif
244 return;
245 }
246
247 oops_in_progress = 1;
248
249 oops_enter();
250
251 /* Amuse the user in a SPARC fashion */
252 if (err) printk(KERN_CRIT
253 " _______________________________ \n"
254 " < Your System ate a SPARC! Gah! >\n"
255 " ------------------------------- \n"
256 " \\ ^__^\n"
257 " (__)\\ )\\/\\\n"
258 " U ||----w |\n"
259 " || ||\n");
260
261 /* unlock the pdc lock if necessary */
262 pdc_emergency_unlock();
263
264 /* maybe the kernel hasn't booted very far yet and hasn't been able
265 * to initialize the serial or STI console. In that case we should
266 * re-enable the pdc console, so that the user will be able to
267 * identify the problem. */
268 if (!console_drivers)
269 pdc_console_restart();
270
271 if (err)
272 printk(KERN_CRIT "%s (pid %d): %s (code %ld)\n",
273 current->comm, task_pid_nr(current), str, err);
274
275 /* Wot's wrong wif bein' racy? */
276 if (current->thread.flags & PARISC_KERNEL_DEATH) {
277 printk(KERN_CRIT "%s() recursion detected.\n", __func__);
278 local_irq_enable();
279 while (1);
280 }
281 current->thread.flags |= PARISC_KERNEL_DEATH;
282
283 show_regs(regs);
284 dump_stack();
285 add_taint(TAINT_DIE);
286
287 if (in_interrupt())
288 panic("Fatal exception in interrupt");
289
290 if (panic_on_oops) {
291 printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
292 ssleep(5);
293 panic("Fatal exception");
294 }
295
296 oops_exit();
297 do_exit(SIGSEGV);
298 }
299
syscall_ipi(int (* syscall)(struct pt_regs *),struct pt_regs * regs)300 int syscall_ipi(int (*syscall) (struct pt_regs *), struct pt_regs *regs)
301 {
302 return syscall(regs);
303 }
304
305 /* gdb uses break 4,8 */
306 #define GDB_BREAK_INSN 0x10004
handle_gdb_break(struct pt_regs * regs,int wot)307 static void handle_gdb_break(struct pt_regs *regs, int wot)
308 {
309 struct siginfo si;
310
311 si.si_signo = SIGTRAP;
312 si.si_errno = 0;
313 si.si_code = wot;
314 si.si_addr = (void __user *) (regs->iaoq[0] & ~3);
315 force_sig_info(SIGTRAP, &si, current);
316 }
317
handle_break(struct pt_regs * regs)318 static void handle_break(struct pt_regs *regs)
319 {
320 unsigned iir = regs->iir;
321
322 if (unlikely(iir == PARISC_BUG_BREAK_INSN && !user_mode(regs))) {
323 /* check if a BUG() or WARN() trapped here. */
324 enum bug_trap_type tt;
325 tt = report_bug(regs->iaoq[0] & ~3, regs);
326 if (tt == BUG_TRAP_TYPE_WARN) {
327 regs->iaoq[0] += 4;
328 regs->iaoq[1] += 4;
329 return; /* return to next instruction when WARN_ON(). */
330 }
331 die_if_kernel("Unknown kernel breakpoint", regs,
332 (tt == BUG_TRAP_TYPE_NONE) ? 9 : 0);
333 }
334
335 #ifdef PRINT_USER_FAULTS
336 if (unlikely(iir != GDB_BREAK_INSN)) {
337 printk(KERN_DEBUG "break %d,%d: pid=%d command='%s'\n",
338 iir & 31, (iir>>13) & ((1<<13)-1),
339 task_pid_nr(current), current->comm);
340 show_regs(regs);
341 }
342 #endif
343
344 /* send standard GDB signal */
345 handle_gdb_break(regs, TRAP_BRKPT);
346 }
347
default_trap(int code,struct pt_regs * regs)348 static void default_trap(int code, struct pt_regs *regs)
349 {
350 printk(KERN_ERR "Trap %d on CPU %d\n", code, smp_processor_id());
351 show_regs(regs);
352 }
353
354 void (*cpu_lpmc) (int code, struct pt_regs *regs) __read_mostly = default_trap;
355
356
transfer_pim_to_trap_frame(struct pt_regs * regs)357 void transfer_pim_to_trap_frame(struct pt_regs *regs)
358 {
359 register int i;
360 extern unsigned int hpmc_pim_data[];
361 struct pdc_hpmc_pim_11 *pim_narrow;
362 struct pdc_hpmc_pim_20 *pim_wide;
363
364 if (boot_cpu_data.cpu_type >= pcxu) {
365
366 pim_wide = (struct pdc_hpmc_pim_20 *)hpmc_pim_data;
367
368 /*
369 * Note: The following code will probably generate a
370 * bunch of truncation error warnings from the compiler.
371 * Could be handled with an ifdef, but perhaps there
372 * is a better way.
373 */
374
375 regs->gr[0] = pim_wide->cr[22];
376
377 for (i = 1; i < 32; i++)
378 regs->gr[i] = pim_wide->gr[i];
379
380 for (i = 0; i < 32; i++)
381 regs->fr[i] = pim_wide->fr[i];
382
383 for (i = 0; i < 8; i++)
384 regs->sr[i] = pim_wide->sr[i];
385
386 regs->iasq[0] = pim_wide->cr[17];
387 regs->iasq[1] = pim_wide->iasq_back;
388 regs->iaoq[0] = pim_wide->cr[18];
389 regs->iaoq[1] = pim_wide->iaoq_back;
390
391 regs->sar = pim_wide->cr[11];
392 regs->iir = pim_wide->cr[19];
393 regs->isr = pim_wide->cr[20];
394 regs->ior = pim_wide->cr[21];
395 }
396 else {
397 pim_narrow = (struct pdc_hpmc_pim_11 *)hpmc_pim_data;
398
399 regs->gr[0] = pim_narrow->cr[22];
400
401 for (i = 1; i < 32; i++)
402 regs->gr[i] = pim_narrow->gr[i];
403
404 for (i = 0; i < 32; i++)
405 regs->fr[i] = pim_narrow->fr[i];
406
407 for (i = 0; i < 8; i++)
408 regs->sr[i] = pim_narrow->sr[i];
409
410 regs->iasq[0] = pim_narrow->cr[17];
411 regs->iasq[1] = pim_narrow->iasq_back;
412 regs->iaoq[0] = pim_narrow->cr[18];
413 regs->iaoq[1] = pim_narrow->iaoq_back;
414
415 regs->sar = pim_narrow->cr[11];
416 regs->iir = pim_narrow->cr[19];
417 regs->isr = pim_narrow->cr[20];
418 regs->ior = pim_narrow->cr[21];
419 }
420
421 /*
422 * The following fields only have meaning if we came through
423 * another path. So just zero them here.
424 */
425
426 regs->ksp = 0;
427 regs->kpc = 0;
428 regs->orig_r28 = 0;
429 }
430
431
432 /*
433 * This routine is called as a last resort when everything else
434 * has gone clearly wrong. We get called for faults in kernel space,
435 * and HPMC's.
436 */
parisc_terminate(char * msg,struct pt_regs * regs,int code,unsigned long offset)437 void parisc_terminate(char *msg, struct pt_regs *regs, int code, unsigned long offset)
438 {
439 static DEFINE_SPINLOCK(terminate_lock);
440
441 oops_in_progress = 1;
442
443 set_eiem(0);
444 local_irq_disable();
445 spin_lock(&terminate_lock);
446
447 /* unlock the pdc lock if necessary */
448 pdc_emergency_unlock();
449
450 /* restart pdc console if necessary */
451 if (!console_drivers)
452 pdc_console_restart();
453
454 /* Not all paths will gutter the processor... */
455 switch(code){
456
457 case 1:
458 transfer_pim_to_trap_frame(regs);
459 break;
460
461 default:
462 /* Fall through */
463 break;
464
465 }
466
467 {
468 /* show_stack(NULL, (unsigned long *)regs->gr[30]); */
469 struct unwind_frame_info info;
470 unwind_frame_init(&info, current, regs);
471 do_show_stack(&info);
472 }
473
474 printk("\n");
475 printk(KERN_CRIT "%s: Code=%d regs=%p (Addr=" RFMT ")\n",
476 msg, code, regs, offset);
477 show_regs(regs);
478
479 spin_unlock(&terminate_lock);
480
481 /* put soft power button back under hardware control;
482 * if the user had pressed it once at any time, the
483 * system will shut down immediately right here. */
484 pdc_soft_power_button(0);
485
486 /* Call kernel panic() so reboot timeouts work properly
487 * FIXME: This function should be on the list of
488 * panic notifiers, and we should call panic
489 * directly from the location that we wish.
490 * e.g. We should not call panic from
491 * parisc_terminate, but rather the oter way around.
492 * This hack works, prints the panic message twice,
493 * and it enables reboot timers!
494 */
495 panic(msg);
496 }
497
handle_interruption(int code,struct pt_regs * regs)498 void notrace handle_interruption(int code, struct pt_regs *regs)
499 {
500 unsigned long fault_address = 0;
501 unsigned long fault_space = 0;
502 struct siginfo si;
503
504 if (code == 1)
505 pdc_console_restart(); /* switch back to pdc if HPMC */
506 else
507 local_irq_enable();
508
509 /* Security check:
510 * If the priority level is still user, and the
511 * faulting space is not equal to the active space
512 * then the user is attempting something in a space
513 * that does not belong to them. Kill the process.
514 *
515 * This is normally the situation when the user
516 * attempts to jump into the kernel space at the
517 * wrong offset, be it at the gateway page or a
518 * random location.
519 *
520 * We cannot normally signal the process because it
521 * could *be* on the gateway page, and processes
522 * executing on the gateway page can't have signals
523 * delivered.
524 *
525 * We merely readjust the address into the users
526 * space, at a destination address of zero, and
527 * allow processing to continue.
528 */
529 if (((unsigned long)regs->iaoq[0] & 3) &&
530 ((unsigned long)regs->iasq[0] != (unsigned long)regs->sr[7])) {
531 /* Kill the user process later */
532 regs->iaoq[0] = 0 | 3;
533 regs->iaoq[1] = regs->iaoq[0] + 4;
534 regs->iasq[0] = regs->iasq[1] = regs->sr[7];
535 regs->gr[0] &= ~PSW_B;
536 return;
537 }
538
539 #if 0
540 printk(KERN_CRIT "Interruption # %d\n", code);
541 #endif
542
543 switch(code) {
544
545 case 1:
546 /* High-priority machine check (HPMC) */
547
548 /* set up a new led state on systems shipped with a LED State panel */
549 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_HPMC);
550
551 parisc_terminate("High Priority Machine Check (HPMC)",
552 regs, code, 0);
553 /* NOT REACHED */
554
555 case 2:
556 /* Power failure interrupt */
557 printk(KERN_CRIT "Power failure interrupt !\n");
558 return;
559
560 case 3:
561 /* Recovery counter trap */
562 regs->gr[0] &= ~PSW_R;
563 if (user_space(regs))
564 handle_gdb_break(regs, TRAP_TRACE);
565 /* else this must be the start of a syscall - just let it run */
566 return;
567
568 case 5:
569 /* Low-priority machine check */
570 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_LPMC);
571
572 flush_cache_all();
573 flush_tlb_all();
574 cpu_lpmc(5, regs);
575 return;
576
577 case 6:
578 /* Instruction TLB miss fault/Instruction page fault */
579 fault_address = regs->iaoq[0];
580 fault_space = regs->iasq[0];
581 break;
582
583 case 8:
584 /* Illegal instruction trap */
585 die_if_kernel("Illegal instruction", regs, code);
586 si.si_code = ILL_ILLOPC;
587 goto give_sigill;
588
589 case 9:
590 /* Break instruction trap */
591 handle_break(regs);
592 return;
593
594 case 10:
595 /* Privileged operation trap */
596 die_if_kernel("Privileged operation", regs, code);
597 si.si_code = ILL_PRVOPC;
598 goto give_sigill;
599
600 case 11:
601 /* Privileged register trap */
602 if ((regs->iir & 0xffdfffe0) == 0x034008a0) {
603
604 /* This is a MFCTL cr26/cr27 to gr instruction.
605 * PCXS traps on this, so we need to emulate it.
606 */
607
608 if (regs->iir & 0x00200000)
609 regs->gr[regs->iir & 0x1f] = mfctl(27);
610 else
611 regs->gr[regs->iir & 0x1f] = mfctl(26);
612
613 regs->iaoq[0] = regs->iaoq[1];
614 regs->iaoq[1] += 4;
615 regs->iasq[0] = regs->iasq[1];
616 return;
617 }
618
619 die_if_kernel("Privileged register usage", regs, code);
620 si.si_code = ILL_PRVREG;
621 give_sigill:
622 si.si_signo = SIGILL;
623 si.si_errno = 0;
624 si.si_addr = (void __user *) regs->iaoq[0];
625 force_sig_info(SIGILL, &si, current);
626 return;
627
628 case 12:
629 /* Overflow Trap, let the userland signal handler do the cleanup */
630 si.si_signo = SIGFPE;
631 si.si_code = FPE_INTOVF;
632 si.si_addr = (void __user *) regs->iaoq[0];
633 force_sig_info(SIGFPE, &si, current);
634 return;
635
636 case 13:
637 /* Conditional Trap
638 The condition succeeds in an instruction which traps
639 on condition */
640 if(user_mode(regs)){
641 si.si_signo = SIGFPE;
642 /* Set to zero, and let the userspace app figure it out from
643 the insn pointed to by si_addr */
644 si.si_code = 0;
645 si.si_addr = (void __user *) regs->iaoq[0];
646 force_sig_info(SIGFPE, &si, current);
647 return;
648 }
649 /* The kernel doesn't want to handle condition codes */
650 break;
651
652 case 14:
653 /* Assist Exception Trap, i.e. floating point exception. */
654 die_if_kernel("Floating point exception", regs, 0); /* quiet */
655 handle_fpe(regs);
656 return;
657
658 case 15:
659 /* Data TLB miss fault/Data page fault */
660 /* Fall through */
661 case 16:
662 /* Non-access instruction TLB miss fault */
663 /* The instruction TLB entry needed for the target address of the FIC
664 is absent, and hardware can't find it, so we get to cleanup */
665 /* Fall through */
666 case 17:
667 /* Non-access data TLB miss fault/Non-access data page fault */
668 /* FIXME:
669 Still need to add slow path emulation code here!
670 If the insn used a non-shadow register, then the tlb
671 handlers could not have their side-effect (e.g. probe
672 writing to a target register) emulated since rfir would
673 erase the changes to said register. Instead we have to
674 setup everything, call this function we are in, and emulate
675 by hand. Technically we need to emulate:
676 fdc,fdce,pdc,"fic,4f",prober,probeir,probew, probeiw
677 */
678 fault_address = regs->ior;
679 fault_space = regs->isr;
680 break;
681
682 case 18:
683 /* PCXS only -- later cpu's split this into types 26,27 & 28 */
684 /* Check for unaligned access */
685 if (check_unaligned(regs)) {
686 handle_unaligned(regs);
687 return;
688 }
689 /* Fall Through */
690 case 26:
691 /* PCXL: Data memory access rights trap */
692 fault_address = regs->ior;
693 fault_space = regs->isr;
694 break;
695
696 case 19:
697 /* Data memory break trap */
698 regs->gr[0] |= PSW_X; /* So we can single-step over the trap */
699 /* fall thru */
700 case 21:
701 /* Page reference trap */
702 handle_gdb_break(regs, TRAP_HWBKPT);
703 return;
704
705 case 25:
706 /* Taken branch trap */
707 regs->gr[0] &= ~PSW_T;
708 if (user_space(regs))
709 handle_gdb_break(regs, TRAP_BRANCH);
710 /* else this must be the start of a syscall - just let it
711 * run.
712 */
713 return;
714
715 case 7:
716 /* Instruction access rights */
717 /* PCXL: Instruction memory protection trap */
718
719 /*
720 * This could be caused by either: 1) a process attempting
721 * to execute within a vma that does not have execute
722 * permission, or 2) an access rights violation caused by a
723 * flush only translation set up by ptep_get_and_clear().
724 * So we check the vma permissions to differentiate the two.
725 * If the vma indicates we have execute permission, then
726 * the cause is the latter one. In this case, we need to
727 * call do_page_fault() to fix the problem.
728 */
729
730 if (user_mode(regs)) {
731 struct vm_area_struct *vma;
732
733 down_read(¤t->mm->mmap_sem);
734 vma = find_vma(current->mm,regs->iaoq[0]);
735 if (vma && (regs->iaoq[0] >= vma->vm_start)
736 && (vma->vm_flags & VM_EXEC)) {
737
738 fault_address = regs->iaoq[0];
739 fault_space = regs->iasq[0];
740
741 up_read(¤t->mm->mmap_sem);
742 break; /* call do_page_fault() */
743 }
744 up_read(¤t->mm->mmap_sem);
745 }
746 /* Fall Through */
747 case 27:
748 /* Data memory protection ID trap */
749 if (code == 27 && !user_mode(regs) &&
750 fixup_exception(regs))
751 return;
752
753 die_if_kernel("Protection id trap", regs, code);
754 si.si_code = SEGV_MAPERR;
755 si.si_signo = SIGSEGV;
756 si.si_errno = 0;
757 if (code == 7)
758 si.si_addr = (void __user *) regs->iaoq[0];
759 else
760 si.si_addr = (void __user *) regs->ior;
761 force_sig_info(SIGSEGV, &si, current);
762 return;
763
764 case 28:
765 /* Unaligned data reference trap */
766 handle_unaligned(regs);
767 return;
768
769 default:
770 if (user_mode(regs)) {
771 #ifdef PRINT_USER_FAULTS
772 printk(KERN_DEBUG "\nhandle_interruption() pid=%d command='%s'\n",
773 task_pid_nr(current), current->comm);
774 show_regs(regs);
775 #endif
776 /* SIGBUS, for lack of a better one. */
777 si.si_signo = SIGBUS;
778 si.si_code = BUS_OBJERR;
779 si.si_errno = 0;
780 si.si_addr = (void __user *) regs->ior;
781 force_sig_info(SIGBUS, &si, current);
782 return;
783 }
784 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC);
785
786 parisc_terminate("Unexpected interruption", regs, code, 0);
787 /* NOT REACHED */
788 }
789
790 if (user_mode(regs)) {
791 if ((fault_space >> SPACEID_SHIFT) != (regs->sr[7] >> SPACEID_SHIFT)) {
792 #ifdef PRINT_USER_FAULTS
793 if (fault_space == 0)
794 printk(KERN_DEBUG "User Fault on Kernel Space ");
795 else
796 printk(KERN_DEBUG "User Fault (long pointer) (fault %d) ",
797 code);
798 printk(KERN_CONT "pid=%d command='%s'\n",
799 task_pid_nr(current), current->comm);
800 show_regs(regs);
801 #endif
802 si.si_signo = SIGSEGV;
803 si.si_errno = 0;
804 si.si_code = SEGV_MAPERR;
805 si.si_addr = (void __user *) regs->ior;
806 force_sig_info(SIGSEGV, &si, current);
807 return;
808 }
809 }
810 else {
811
812 /*
813 * The kernel should never fault on its own address space,
814 * unless pagefault_disable() was called before.
815 */
816
817 if (fault_space == 0 && !in_atomic())
818 {
819 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC);
820 parisc_terminate("Kernel Fault", regs, code, fault_address);
821 }
822 }
823
824 do_page_fault(regs, code, fault_address);
825 }
826
827
check_ivt(void * iva)828 int __init check_ivt(void *iva)
829 {
830 extern u32 os_hpmc_size;
831 extern const u32 os_hpmc[];
832
833 int i;
834 u32 check = 0;
835 u32 *ivap;
836 u32 *hpmcp;
837 u32 length;
838
839 if (strcmp((char *)iva, "cows can fly"))
840 return -1;
841
842 ivap = (u32 *)iva;
843
844 for (i = 0; i < 8; i++)
845 *ivap++ = 0;
846
847 /* Compute Checksum for HPMC handler */
848 length = os_hpmc_size;
849 ivap[7] = length;
850
851 hpmcp = (u32 *)os_hpmc;
852
853 for (i=0; i<length/4; i++)
854 check += *hpmcp++;
855
856 for (i=0; i<8; i++)
857 check += ivap[i];
858
859 ivap[5] = -check;
860
861 return 0;
862 }
863
864 #ifndef CONFIG_64BIT
865 extern const void fault_vector_11;
866 #endif
867 extern const void fault_vector_20;
868
trap_init(void)869 void __init trap_init(void)
870 {
871 void *iva;
872
873 if (boot_cpu_data.cpu_type >= pcxu)
874 iva = (void *) &fault_vector_20;
875 else
876 #ifdef CONFIG_64BIT
877 panic("Can't boot 64-bit OS on PA1.1 processor!");
878 #else
879 iva = (void *) &fault_vector_11;
880 #endif
881
882 if (check_ivt(iva))
883 panic("IVT invalid");
884 }
885