1 /* traps.c: high-level exception handler for FR-V
2 *
3 * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12 #include <linux/sched.h>
13 #include <linux/signal.h>
14 #include <linux/kernel.h>
15 #include <linux/mm.h>
16 #include <linux/types.h>
17 #include <linux/user.h>
18 #include <linux/string.h>
19 #include <linux/linkage.h>
20 #include <linux/init.h>
21 #include <linux/module.h>
22
23 #include <asm/asm-offsets.h>
24 #include <asm/setup.h>
25 #include <asm/fpu.h>
26 #include <asm/uaccess.h>
27 #include <asm/pgtable.h>
28 #include <asm/siginfo.h>
29 #include <asm/unaligned.h>
30
31 void show_backtrace(struct pt_regs *, unsigned long);
32
33 extern asmlinkage void __break_hijack_kernel_event(void);
34
35 /*****************************************************************************/
36 /*
37 * instruction access error
38 */
insn_access_error(unsigned long esfr1,unsigned long epcr0,unsigned long esr0)39 asmlinkage void insn_access_error(unsigned long esfr1, unsigned long epcr0, unsigned long esr0)
40 {
41 siginfo_t info;
42
43 die_if_kernel("-- Insn Access Error --\n"
44 "EPCR0 : %08lx\n"
45 "ESR0 : %08lx\n",
46 epcr0, esr0);
47
48 info.si_signo = SIGSEGV;
49 info.si_code = SEGV_ACCERR;
50 info.si_errno = 0;
51 info.si_addr = (void __user *) ((epcr0 & EPCR0_V) ? (epcr0 & EPCR0_PC) : __frame->pc);
52
53 force_sig_info(info.si_signo, &info, current);
54 } /* end insn_access_error() */
55
56 /*****************************************************************************/
57 /*
58 * handler for:
59 * - illegal instruction
60 * - privileged instruction
61 * - unsupported trap
62 * - debug exceptions
63 */
illegal_instruction(unsigned long esfr1,unsigned long epcr0,unsigned long esr0)64 asmlinkage void illegal_instruction(unsigned long esfr1, unsigned long epcr0, unsigned long esr0)
65 {
66 siginfo_t info;
67
68 die_if_kernel("-- Illegal Instruction --\n"
69 "EPCR0 : %08lx\n"
70 "ESR0 : %08lx\n"
71 "ESFR1 : %08lx\n",
72 epcr0, esr0, esfr1);
73
74 info.si_errno = 0;
75 info.si_addr = (void __user *) ((epcr0 & EPCR0_V) ? (epcr0 & EPCR0_PC) : __frame->pc);
76
77 switch (__frame->tbr & TBR_TT) {
78 case TBR_TT_ILLEGAL_INSTR:
79 info.si_signo = SIGILL;
80 info.si_code = ILL_ILLOPC;
81 break;
82 case TBR_TT_PRIV_INSTR:
83 info.si_signo = SIGILL;
84 info.si_code = ILL_PRVOPC;
85 break;
86 case TBR_TT_TRAP2 ... TBR_TT_TRAP126:
87 info.si_signo = SIGILL;
88 info.si_code = ILL_ILLTRP;
89 break;
90 /* GDB uses "tira gr0, #1" as a breakpoint instruction. */
91 case TBR_TT_TRAP1:
92 case TBR_TT_BREAK:
93 info.si_signo = SIGTRAP;
94 info.si_code =
95 (__frame->__status & REG__STATUS_STEPPED) ? TRAP_TRACE : TRAP_BRKPT;
96 break;
97 }
98
99 force_sig_info(info.si_signo, &info, current);
100 } /* end illegal_instruction() */
101
102 /*****************************************************************************/
103 /*
104 * handle atomic operations with errors
105 * - arguments in gr8, gr9, gr10
106 * - original memory value placed in gr5
107 * - replacement memory value placed in gr9
108 */
atomic_operation(unsigned long esfr1,unsigned long epcr0,unsigned long esr0)109 asmlinkage void atomic_operation(unsigned long esfr1, unsigned long epcr0,
110 unsigned long esr0)
111 {
112 static DEFINE_SPINLOCK(atomic_op_lock);
113 unsigned long x, y, z;
114 unsigned long __user *p;
115 mm_segment_t oldfs;
116 siginfo_t info;
117 int ret;
118
119 y = 0;
120 z = 0;
121
122 oldfs = get_fs();
123 if (!user_mode(__frame))
124 set_fs(KERNEL_DS);
125
126 switch (__frame->tbr & TBR_TT) {
127 /* TIRA gr0,#120
128 * u32 __atomic_user_cmpxchg32(u32 *ptr, u32 test, u32 new)
129 */
130 case TBR_TT_ATOMIC_CMPXCHG32:
131 p = (unsigned long __user *) __frame->gr8;
132 x = __frame->gr9;
133 y = __frame->gr10;
134
135 for (;;) {
136 ret = get_user(z, p);
137 if (ret < 0)
138 goto error;
139
140 if (z != x)
141 goto done;
142
143 spin_lock_irq(&atomic_op_lock);
144
145 if (__get_user(z, p) == 0) {
146 if (z != x)
147 goto done2;
148
149 if (__put_user(y, p) == 0)
150 goto done2;
151 goto error2;
152 }
153
154 spin_unlock_irq(&atomic_op_lock);
155 }
156
157 /* TIRA gr0,#121
158 * u32 __atomic_kernel_xchg32(void *v, u32 new)
159 */
160 case TBR_TT_ATOMIC_XCHG32:
161 p = (unsigned long __user *) __frame->gr8;
162 y = __frame->gr9;
163
164 for (;;) {
165 ret = get_user(z, p);
166 if (ret < 0)
167 goto error;
168
169 spin_lock_irq(&atomic_op_lock);
170
171 if (__get_user(z, p) == 0) {
172 if (__put_user(y, p) == 0)
173 goto done2;
174 goto error2;
175 }
176
177 spin_unlock_irq(&atomic_op_lock);
178 }
179
180 /* TIRA gr0,#122
181 * ulong __atomic_kernel_XOR_return(ulong i, ulong *v)
182 */
183 case TBR_TT_ATOMIC_XOR:
184 p = (unsigned long __user *) __frame->gr8;
185 x = __frame->gr9;
186
187 for (;;) {
188 ret = get_user(z, p);
189 if (ret < 0)
190 goto error;
191
192 spin_lock_irq(&atomic_op_lock);
193
194 if (__get_user(z, p) == 0) {
195 y = x ^ z;
196 if (__put_user(y, p) == 0)
197 goto done2;
198 goto error2;
199 }
200
201 spin_unlock_irq(&atomic_op_lock);
202 }
203
204 /* TIRA gr0,#123
205 * ulong __atomic_kernel_OR_return(ulong i, ulong *v)
206 */
207 case TBR_TT_ATOMIC_OR:
208 p = (unsigned long __user *) __frame->gr8;
209 x = __frame->gr9;
210
211 for (;;) {
212 ret = get_user(z, p);
213 if (ret < 0)
214 goto error;
215
216 spin_lock_irq(&atomic_op_lock);
217
218 if (__get_user(z, p) == 0) {
219 y = x ^ z;
220 if (__put_user(y, p) == 0)
221 goto done2;
222 goto error2;
223 }
224
225 spin_unlock_irq(&atomic_op_lock);
226 }
227
228 /* TIRA gr0,#124
229 * ulong __atomic_kernel_AND_return(ulong i, ulong *v)
230 */
231 case TBR_TT_ATOMIC_AND:
232 p = (unsigned long __user *) __frame->gr8;
233 x = __frame->gr9;
234
235 for (;;) {
236 ret = get_user(z, p);
237 if (ret < 0)
238 goto error;
239
240 spin_lock_irq(&atomic_op_lock);
241
242 if (__get_user(z, p) == 0) {
243 y = x & z;
244 if (__put_user(y, p) == 0)
245 goto done2;
246 goto error2;
247 }
248
249 spin_unlock_irq(&atomic_op_lock);
250 }
251
252 /* TIRA gr0,#125
253 * int __atomic_user_sub_return(atomic_t *v, int i)
254 */
255 case TBR_TT_ATOMIC_SUB:
256 p = (unsigned long __user *) __frame->gr8;
257 x = __frame->gr9;
258
259 for (;;) {
260 ret = get_user(z, p);
261 if (ret < 0)
262 goto error;
263
264 spin_lock_irq(&atomic_op_lock);
265
266 if (__get_user(z, p) == 0) {
267 y = z - x;
268 if (__put_user(y, p) == 0)
269 goto done2;
270 goto error2;
271 }
272
273 spin_unlock_irq(&atomic_op_lock);
274 }
275
276 /* TIRA gr0,#126
277 * int __atomic_user_add_return(atomic_t *v, int i)
278 */
279 case TBR_TT_ATOMIC_ADD:
280 p = (unsigned long __user *) __frame->gr8;
281 x = __frame->gr9;
282
283 for (;;) {
284 ret = get_user(z, p);
285 if (ret < 0)
286 goto error;
287
288 spin_lock_irq(&atomic_op_lock);
289
290 if (__get_user(z, p) == 0) {
291 y = z + x;
292 if (__put_user(y, p) == 0)
293 goto done2;
294 goto error2;
295 }
296
297 spin_unlock_irq(&atomic_op_lock);
298 }
299
300 default:
301 BUG();
302 }
303
304 done2:
305 spin_unlock_irq(&atomic_op_lock);
306 done:
307 if (!user_mode(__frame))
308 set_fs(oldfs);
309 __frame->gr5 = z;
310 __frame->gr9 = y;
311 return;
312
313 error2:
314 spin_unlock_irq(&atomic_op_lock);
315 error:
316 if (!user_mode(__frame))
317 set_fs(oldfs);
318 __frame->pc -= 4;
319
320 die_if_kernel("-- Atomic Op Error --\n");
321
322 info.si_signo = SIGSEGV;
323 info.si_code = SEGV_ACCERR;
324 info.si_errno = 0;
325 info.si_addr = (void __user *) __frame->pc;
326
327 force_sig_info(info.si_signo, &info, current);
328 }
329
330 /*****************************************************************************/
331 /*
332 *
333 */
media_exception(unsigned long msr0,unsigned long msr1)334 asmlinkage void media_exception(unsigned long msr0, unsigned long msr1)
335 {
336 siginfo_t info;
337
338 die_if_kernel("-- Media Exception --\n"
339 "MSR0 : %08lx\n"
340 "MSR1 : %08lx\n",
341 msr0, msr1);
342
343 info.si_signo = SIGFPE;
344 info.si_code = FPE_MDAOVF;
345 info.si_errno = 0;
346 info.si_addr = (void __user *) __frame->pc;
347
348 force_sig_info(info.si_signo, &info, current);
349 } /* end media_exception() */
350
351 /*****************************************************************************/
352 /*
353 * instruction or data access exception
354 */
memory_access_exception(unsigned long esr0,unsigned long ear0,unsigned long epcr0)355 asmlinkage void memory_access_exception(unsigned long esr0,
356 unsigned long ear0,
357 unsigned long epcr0)
358 {
359 siginfo_t info;
360
361 #ifdef CONFIG_MMU
362 unsigned long fixup;
363
364 fixup = search_exception_table(__frame->pc);
365 if (fixup) {
366 __frame->pc = fixup;
367 return;
368 }
369 #endif
370
371 die_if_kernel("-- Memory Access Exception --\n"
372 "ESR0 : %08lx\n"
373 "EAR0 : %08lx\n"
374 "EPCR0 : %08lx\n",
375 esr0, ear0, epcr0);
376
377 info.si_signo = SIGSEGV;
378 info.si_code = SEGV_ACCERR;
379 info.si_errno = 0;
380 info.si_addr = NULL;
381
382 if ((esr0 & (ESRx_VALID | ESR0_EAV)) == (ESRx_VALID | ESR0_EAV))
383 info.si_addr = (void __user *) ear0;
384
385 force_sig_info(info.si_signo, &info, current);
386
387 } /* end memory_access_exception() */
388
389 /*****************************************************************************/
390 /*
391 * data access error
392 * - double-word data load from CPU control area (0xFExxxxxx)
393 * - read performed on inactive or self-refreshing SDRAM
394 * - error notification from slave device
395 * - misaligned address
396 * - access to out of bounds memory region
397 * - user mode accessing privileged memory region
398 * - write to R/O memory region
399 */
data_access_error(unsigned long esfr1,unsigned long esr15,unsigned long ear15)400 asmlinkage void data_access_error(unsigned long esfr1, unsigned long esr15, unsigned long ear15)
401 {
402 siginfo_t info;
403
404 die_if_kernel("-- Data Access Error --\n"
405 "ESR15 : %08lx\n"
406 "EAR15 : %08lx\n",
407 esr15, ear15);
408
409 info.si_signo = SIGSEGV;
410 info.si_code = SEGV_ACCERR;
411 info.si_errno = 0;
412 info.si_addr = (void __user *)
413 (((esr15 & (ESRx_VALID|ESR15_EAV)) == (ESRx_VALID|ESR15_EAV)) ? ear15 : 0);
414
415 force_sig_info(info.si_signo, &info, current);
416 } /* end data_access_error() */
417
418 /*****************************************************************************/
419 /*
420 * data store error - should only happen if accessing inactive or self-refreshing SDRAM
421 */
data_store_error(unsigned long esfr1,unsigned long esr15)422 asmlinkage void data_store_error(unsigned long esfr1, unsigned long esr15)
423 {
424 die_if_kernel("-- Data Store Error --\n"
425 "ESR15 : %08lx\n",
426 esr15);
427 BUG();
428 } /* end data_store_error() */
429
430 /*****************************************************************************/
431 /*
432 *
433 */
division_exception(unsigned long esfr1,unsigned long esr0,unsigned long isr)434 asmlinkage void division_exception(unsigned long esfr1, unsigned long esr0, unsigned long isr)
435 {
436 siginfo_t info;
437
438 die_if_kernel("-- Division Exception --\n"
439 "ESR0 : %08lx\n"
440 "ISR : %08lx\n",
441 esr0, isr);
442
443 info.si_signo = SIGFPE;
444 info.si_code = FPE_INTDIV;
445 info.si_errno = 0;
446 info.si_addr = (void __user *) __frame->pc;
447
448 force_sig_info(info.si_signo, &info, current);
449 } /* end division_exception() */
450
451 /*****************************************************************************/
452 /*
453 *
454 */
compound_exception(unsigned long esfr1,unsigned long esr0,unsigned long esr14,unsigned long esr15,unsigned long msr0,unsigned long msr1)455 asmlinkage void compound_exception(unsigned long esfr1,
456 unsigned long esr0, unsigned long esr14, unsigned long esr15,
457 unsigned long msr0, unsigned long msr1)
458 {
459 die_if_kernel("-- Compound Exception --\n"
460 "ESR0 : %08lx\n"
461 "ESR15 : %08lx\n"
462 "ESR15 : %08lx\n"
463 "MSR0 : %08lx\n"
464 "MSR1 : %08lx\n",
465 esr0, esr14, esr15, msr0, msr1);
466 BUG();
467 } /* end compound_exception() */
468
469 /*****************************************************************************/
470 /*
471 * The architecture-independent backtrace generator
472 */
dump_stack(void)473 void dump_stack(void)
474 {
475 show_stack(NULL, NULL);
476 }
477
478 EXPORT_SYMBOL(dump_stack);
479
show_stack(struct task_struct * task,unsigned long * sp)480 void show_stack(struct task_struct *task, unsigned long *sp)
481 {
482 }
483
show_trace_task(struct task_struct * tsk)484 void show_trace_task(struct task_struct *tsk)
485 {
486 printk("CONTEXT: stack=0x%lx frame=0x%p LR=0x%lx RET=0x%lx\n",
487 tsk->thread.sp, tsk->thread.frame, tsk->thread.lr, tsk->thread.sched_lr);
488 }
489
490 static const char *regnames[] = {
491 "PSR ", "ISR ", "CCR ", "CCCR",
492 "LR ", "LCR ", "PC ", "_stt",
493 "sys ", "GR8*", "GNE0", "GNE1",
494 "IACH", "IACL",
495 "TBR ", "SP ", "FP ", "GR3 ",
496 "GR4 ", "GR5 ", "GR6 ", "GR7 ",
497 "GR8 ", "GR9 ", "GR10", "GR11",
498 "GR12", "GR13", "GR14", "GR15",
499 "GR16", "GR17", "GR18", "GR19",
500 "GR20", "GR21", "GR22", "GR23",
501 "GR24", "GR25", "GR26", "GR27",
502 "EFRM", "CURR", "GR30", "BFRM"
503 };
504
show_regs(struct pt_regs * regs)505 void show_regs(struct pt_regs *regs)
506 {
507 unsigned long *reg;
508 int loop;
509
510 printk("\n");
511
512 printk("Frame: @%08lx [%s]\n",
513 (unsigned long) regs,
514 regs->psr & PSR_S ? "kernel" : "user");
515
516 reg = (unsigned long *) regs;
517 for (loop = 0; loop < NR_PT_REGS; loop++) {
518 printk("%s %08lx", regnames[loop + 0], reg[loop + 0]);
519
520 if (loop == NR_PT_REGS - 1 || loop % 5 == 4)
521 printk("\n");
522 else
523 printk(" | ");
524 }
525
526 printk("Process %s (pid: %d)\n", current->comm, current->pid);
527 }
528
die_if_kernel(const char * str,...)529 void die_if_kernel(const char *str, ...)
530 {
531 char buffer[256];
532 va_list va;
533
534 if (user_mode(__frame))
535 return;
536
537 va_start(va, str);
538 vsprintf(buffer, str, va);
539 va_end(va);
540
541 console_verbose();
542 printk("\n===================================\n");
543 printk("%s\n", buffer);
544 show_backtrace(__frame, 0);
545
546 __break_hijack_kernel_event();
547 do_exit(SIGSEGV);
548 }
549
550 /*****************************************************************************/
551 /*
552 * dump the contents of an exception frame
553 */
show_backtrace_regs(struct pt_regs * frame)554 static void show_backtrace_regs(struct pt_regs *frame)
555 {
556 unsigned long *reg;
557 int loop;
558
559 /* print the registers for this frame */
560 printk("<-- %s Frame: @%p -->\n",
561 frame->psr & PSR_S ? "Kernel Mode" : "User Mode",
562 frame);
563
564 reg = (unsigned long *) frame;
565 for (loop = 0; loop < NR_PT_REGS; loop++) {
566 printk("%s %08lx", regnames[loop + 0], reg[loop + 0]);
567
568 if (loop == NR_PT_REGS - 1 || loop % 5 == 4)
569 printk("\n");
570 else
571 printk(" | ");
572 }
573
574 printk("--------\n");
575 } /* end show_backtrace_regs() */
576
577 /*****************************************************************************/
578 /*
579 * generate a backtrace of the kernel stack
580 */
show_backtrace(struct pt_regs * frame,unsigned long sp)581 void show_backtrace(struct pt_regs *frame, unsigned long sp)
582 {
583 struct pt_regs *frame0;
584 unsigned long tos = 0, stop = 0, base;
585 int format;
586
587 base = ((((unsigned long) frame) + 8191) & ~8191) - sizeof(struct user_context);
588 frame0 = (struct pt_regs *) base;
589
590 if (sp) {
591 tos = sp;
592 stop = (unsigned long) frame;
593 }
594
595 printk("\nProcess %s (pid: %d)\n\n", current->comm, current->pid);
596
597 for (;;) {
598 /* dump stack segment between frames */
599 //printk("%08lx -> %08lx\n", tos, stop);
600 format = 0;
601 while (tos < stop) {
602 if (format == 0)
603 printk(" %04lx :", tos & 0xffff);
604
605 printk(" %08lx", *(unsigned long *) tos);
606
607 tos += 4;
608 format++;
609 if (format == 8) {
610 printk("\n");
611 format = 0;
612 }
613 }
614
615 if (format > 0)
616 printk("\n");
617
618 /* dump frame 0 outside of the loop */
619 if (frame == frame0)
620 break;
621
622 tos = frame->sp;
623 if (((unsigned long) frame) + sizeof(*frame) != tos) {
624 printk("-- TOS %08lx does not follow frame %p --\n",
625 tos, frame);
626 break;
627 }
628
629 show_backtrace_regs(frame);
630
631 /* dump the stack between this frame and the next */
632 stop = (unsigned long) frame->next_frame;
633 if (stop != base &&
634 (stop < tos ||
635 stop > base ||
636 (stop < base && stop + sizeof(*frame) > base) ||
637 stop & 3)) {
638 printk("-- next_frame %08lx is invalid (range %08lx-%08lx) --\n",
639 stop, tos, base);
640 break;
641 }
642
643 /* move to next frame */
644 frame = frame->next_frame;
645 }
646
647 /* we can always dump frame 0, even if the rest of the stack is corrupt */
648 show_backtrace_regs(frame0);
649
650 } /* end show_backtrace() */
651
652 /*****************************************************************************/
653 /*
654 * initialise traps
655 */
trap_init(void)656 void __init trap_init (void)
657 {
658 } /* end trap_init() */
659