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/system.h>
27 #include <asm/uaccess.h>
28 #include <asm/pgtable.h>
29 #include <asm/siginfo.h>
30 #include <asm/unaligned.h>
31
32 void show_backtrace(struct pt_regs *, unsigned long);
33
34 extern asmlinkage void __break_hijack_kernel_event(void);
35
36 /*****************************************************************************/
37 /*
38 * instruction access error
39 */
insn_access_error(unsigned long esfr1,unsigned long epcr0,unsigned long esr0)40 asmlinkage void insn_access_error(unsigned long esfr1, unsigned long epcr0, unsigned long esr0)
41 {
42 siginfo_t info;
43
44 die_if_kernel("-- Insn Access Error --\n"
45 "EPCR0 : %08lx\n"
46 "ESR0 : %08lx\n",
47 epcr0, esr0);
48
49 info.si_signo = SIGSEGV;
50 info.si_code = SEGV_ACCERR;
51 info.si_errno = 0;
52 info.si_addr = (void __user *) ((epcr0 & EPCR0_V) ? (epcr0 & EPCR0_PC) : __frame->pc);
53
54 force_sig_info(info.si_signo, &info, current);
55 } /* end insn_access_error() */
56
57 /*****************************************************************************/
58 /*
59 * handler for:
60 * - illegal instruction
61 * - privileged instruction
62 * - unsupported trap
63 * - debug exceptions
64 */
illegal_instruction(unsigned long esfr1,unsigned long epcr0,unsigned long esr0)65 asmlinkage void illegal_instruction(unsigned long esfr1, unsigned long epcr0, unsigned long esr0)
66 {
67 siginfo_t info;
68
69 die_if_kernel("-- Illegal Instruction --\n"
70 "EPCR0 : %08lx\n"
71 "ESR0 : %08lx\n"
72 "ESFR1 : %08lx\n",
73 epcr0, esr0, esfr1);
74
75 info.si_errno = 0;
76 info.si_addr = (void __user *) ((epcr0 & EPCR0_V) ? (epcr0 & EPCR0_PC) : __frame->pc);
77
78 switch (__frame->tbr & TBR_TT) {
79 case TBR_TT_ILLEGAL_INSTR:
80 info.si_signo = SIGILL;
81 info.si_code = ILL_ILLOPC;
82 break;
83 case TBR_TT_PRIV_INSTR:
84 info.si_signo = SIGILL;
85 info.si_code = ILL_PRVOPC;
86 break;
87 case TBR_TT_TRAP2 ... TBR_TT_TRAP126:
88 info.si_signo = SIGILL;
89 info.si_code = ILL_ILLTRP;
90 break;
91 /* GDB uses "tira gr0, #1" as a breakpoint instruction. */
92 case TBR_TT_TRAP1:
93 case TBR_TT_BREAK:
94 info.si_signo = SIGTRAP;
95 info.si_code =
96 (__frame->__status & REG__STATUS_STEPPED) ? TRAP_TRACE : TRAP_BRKPT;
97 break;
98 }
99
100 force_sig_info(info.si_signo, &info, current);
101 } /* end illegal_instruction() */
102
103 /*****************************************************************************/
104 /*
105 * handle atomic operations with errors
106 * - arguments in gr8, gr9, gr10
107 * - original memory value placed in gr5
108 * - replacement memory value placed in gr9
109 */
atomic_operation(unsigned long esfr1,unsigned long epcr0,unsigned long esr0)110 asmlinkage void atomic_operation(unsigned long esfr1, unsigned long epcr0,
111 unsigned long esr0)
112 {
113 static DEFINE_SPINLOCK(atomic_op_lock);
114 unsigned long x, y, z;
115 unsigned long __user *p;
116 mm_segment_t oldfs;
117 siginfo_t info;
118 int ret;
119
120 y = 0;
121 z = 0;
122
123 oldfs = get_fs();
124 if (!user_mode(__frame))
125 set_fs(KERNEL_DS);
126
127 switch (__frame->tbr & TBR_TT) {
128 /* TIRA gr0,#120
129 * u32 __atomic_user_cmpxchg32(u32 *ptr, u32 test, u32 new)
130 */
131 case TBR_TT_ATOMIC_CMPXCHG32:
132 p = (unsigned long __user *) __frame->gr8;
133 x = __frame->gr9;
134 y = __frame->gr10;
135
136 for (;;) {
137 ret = get_user(z, p);
138 if (ret < 0)
139 goto error;
140
141 if (z != x)
142 goto done;
143
144 spin_lock_irq(&atomic_op_lock);
145
146 if (__get_user(z, p) == 0) {
147 if (z != x)
148 goto done2;
149
150 if (__put_user(y, p) == 0)
151 goto done2;
152 goto error2;
153 }
154
155 spin_unlock_irq(&atomic_op_lock);
156 }
157
158 /* TIRA gr0,#121
159 * u32 __atomic_kernel_xchg32(void *v, u32 new)
160 */
161 case TBR_TT_ATOMIC_XCHG32:
162 p = (unsigned long __user *) __frame->gr8;
163 y = __frame->gr9;
164
165 for (;;) {
166 ret = get_user(z, p);
167 if (ret < 0)
168 goto error;
169
170 spin_lock_irq(&atomic_op_lock);
171
172 if (__get_user(z, p) == 0) {
173 if (__put_user(y, p) == 0)
174 goto done2;
175 goto error2;
176 }
177
178 spin_unlock_irq(&atomic_op_lock);
179 }
180
181 /* TIRA gr0,#122
182 * ulong __atomic_kernel_XOR_return(ulong i, ulong *v)
183 */
184 case TBR_TT_ATOMIC_XOR:
185 p = (unsigned long __user *) __frame->gr8;
186 x = __frame->gr9;
187
188 for (;;) {
189 ret = get_user(z, p);
190 if (ret < 0)
191 goto error;
192
193 spin_lock_irq(&atomic_op_lock);
194
195 if (__get_user(z, p) == 0) {
196 y = x ^ z;
197 if (__put_user(y, p) == 0)
198 goto done2;
199 goto error2;
200 }
201
202 spin_unlock_irq(&atomic_op_lock);
203 }
204
205 /* TIRA gr0,#123
206 * ulong __atomic_kernel_OR_return(ulong i, ulong *v)
207 */
208 case TBR_TT_ATOMIC_OR:
209 p = (unsigned long __user *) __frame->gr8;
210 x = __frame->gr9;
211
212 for (;;) {
213 ret = get_user(z, p);
214 if (ret < 0)
215 goto error;
216
217 spin_lock_irq(&atomic_op_lock);
218
219 if (__get_user(z, p) == 0) {
220 y = x ^ z;
221 if (__put_user(y, p) == 0)
222 goto done2;
223 goto error2;
224 }
225
226 spin_unlock_irq(&atomic_op_lock);
227 }
228
229 /* TIRA gr0,#124
230 * ulong __atomic_kernel_AND_return(ulong i, ulong *v)
231 */
232 case TBR_TT_ATOMIC_AND:
233 p = (unsigned long __user *) __frame->gr8;
234 x = __frame->gr9;
235
236 for (;;) {
237 ret = get_user(z, p);
238 if (ret < 0)
239 goto error;
240
241 spin_lock_irq(&atomic_op_lock);
242
243 if (__get_user(z, p) == 0) {
244 y = x & z;
245 if (__put_user(y, p) == 0)
246 goto done2;
247 goto error2;
248 }
249
250 spin_unlock_irq(&atomic_op_lock);
251 }
252
253 /* TIRA gr0,#125
254 * int __atomic_user_sub_return(atomic_t *v, int i)
255 */
256 case TBR_TT_ATOMIC_SUB:
257 p = (unsigned long __user *) __frame->gr8;
258 x = __frame->gr9;
259
260 for (;;) {
261 ret = get_user(z, p);
262 if (ret < 0)
263 goto error;
264
265 spin_lock_irq(&atomic_op_lock);
266
267 if (__get_user(z, p) == 0) {
268 y = z - x;
269 if (__put_user(y, p) == 0)
270 goto done2;
271 goto error2;
272 }
273
274 spin_unlock_irq(&atomic_op_lock);
275 }
276
277 /* TIRA gr0,#126
278 * int __atomic_user_add_return(atomic_t *v, int i)
279 */
280 case TBR_TT_ATOMIC_ADD:
281 p = (unsigned long __user *) __frame->gr8;
282 x = __frame->gr9;
283
284 for (;;) {
285 ret = get_user(z, p);
286 if (ret < 0)
287 goto error;
288
289 spin_lock_irq(&atomic_op_lock);
290
291 if (__get_user(z, p) == 0) {
292 y = z + x;
293 if (__put_user(y, p) == 0)
294 goto done2;
295 goto error2;
296 }
297
298 spin_unlock_irq(&atomic_op_lock);
299 }
300
301 default:
302 BUG();
303 }
304
305 done2:
306 spin_unlock_irq(&atomic_op_lock);
307 done:
308 if (!user_mode(__frame))
309 set_fs(oldfs);
310 __frame->gr5 = z;
311 __frame->gr9 = y;
312 return;
313
314 error2:
315 spin_unlock_irq(&atomic_op_lock);
316 error:
317 if (!user_mode(__frame))
318 set_fs(oldfs);
319 __frame->pc -= 4;
320
321 die_if_kernel("-- Atomic Op Error --\n");
322
323 info.si_signo = SIGSEGV;
324 info.si_code = SEGV_ACCERR;
325 info.si_errno = 0;
326 info.si_addr = (void __user *) __frame->pc;
327
328 force_sig_info(info.si_signo, &info, current);
329 }
330
331 /*****************************************************************************/
332 /*
333 *
334 */
media_exception(unsigned long msr0,unsigned long msr1)335 asmlinkage void media_exception(unsigned long msr0, unsigned long msr1)
336 {
337 siginfo_t info;
338
339 die_if_kernel("-- Media Exception --\n"
340 "MSR0 : %08lx\n"
341 "MSR1 : %08lx\n",
342 msr0, msr1);
343
344 info.si_signo = SIGFPE;
345 info.si_code = FPE_MDAOVF;
346 info.si_errno = 0;
347 info.si_addr = (void __user *) __frame->pc;
348
349 force_sig_info(info.si_signo, &info, current);
350 } /* end media_exception() */
351
352 /*****************************************************************************/
353 /*
354 * instruction or data access exception
355 */
memory_access_exception(unsigned long esr0,unsigned long ear0,unsigned long epcr0)356 asmlinkage void memory_access_exception(unsigned long esr0,
357 unsigned long ear0,
358 unsigned long epcr0)
359 {
360 siginfo_t info;
361
362 #ifdef CONFIG_MMU
363 unsigned long fixup;
364
365 fixup = search_exception_table(__frame->pc);
366 if (fixup) {
367 __frame->pc = fixup;
368 return;
369 }
370 #endif
371
372 die_if_kernel("-- Memory Access Exception --\n"
373 "ESR0 : %08lx\n"
374 "EAR0 : %08lx\n"
375 "EPCR0 : %08lx\n",
376 esr0, ear0, epcr0);
377
378 info.si_signo = SIGSEGV;
379 info.si_code = SEGV_ACCERR;
380 info.si_errno = 0;
381 info.si_addr = NULL;
382
383 if ((esr0 & (ESRx_VALID | ESR0_EAV)) == (ESRx_VALID | ESR0_EAV))
384 info.si_addr = (void __user *) ear0;
385
386 force_sig_info(info.si_signo, &info, current);
387
388 } /* end memory_access_exception() */
389
390 /*****************************************************************************/
391 /*
392 * data access error
393 * - double-word data load from CPU control area (0xFExxxxxx)
394 * - read performed on inactive or self-refreshing SDRAM
395 * - error notification from slave device
396 * - misaligned address
397 * - access to out of bounds memory region
398 * - user mode accessing privileged memory region
399 * - write to R/O memory region
400 */
data_access_error(unsigned long esfr1,unsigned long esr15,unsigned long ear15)401 asmlinkage void data_access_error(unsigned long esfr1, unsigned long esr15, unsigned long ear15)
402 {
403 siginfo_t info;
404
405 die_if_kernel("-- Data Access Error --\n"
406 "ESR15 : %08lx\n"
407 "EAR15 : %08lx\n",
408 esr15, ear15);
409
410 info.si_signo = SIGSEGV;
411 info.si_code = SEGV_ACCERR;
412 info.si_errno = 0;
413 info.si_addr = (void __user *)
414 (((esr15 & (ESRx_VALID|ESR15_EAV)) == (ESRx_VALID|ESR15_EAV)) ? ear15 : 0);
415
416 force_sig_info(info.si_signo, &info, current);
417 } /* end data_access_error() */
418
419 /*****************************************************************************/
420 /*
421 * data store error - should only happen if accessing inactive or self-refreshing SDRAM
422 */
data_store_error(unsigned long esfr1,unsigned long esr15)423 asmlinkage void data_store_error(unsigned long esfr1, unsigned long esr15)
424 {
425 die_if_kernel("-- Data Store Error --\n"
426 "ESR15 : %08lx\n",
427 esr15);
428 BUG();
429 } /* end data_store_error() */
430
431 /*****************************************************************************/
432 /*
433 *
434 */
division_exception(unsigned long esfr1,unsigned long esr0,unsigned long isr)435 asmlinkage void division_exception(unsigned long esfr1, unsigned long esr0, unsigned long isr)
436 {
437 siginfo_t info;
438
439 die_if_kernel("-- Division Exception --\n"
440 "ESR0 : %08lx\n"
441 "ISR : %08lx\n",
442 esr0, isr);
443
444 info.si_signo = SIGFPE;
445 info.si_code = FPE_INTDIV;
446 info.si_errno = 0;
447 info.si_addr = (void __user *) __frame->pc;
448
449 force_sig_info(info.si_signo, &info, current);
450 } /* end division_exception() */
451
452 /*****************************************************************************/
453 /*
454 *
455 */
compound_exception(unsigned long esfr1,unsigned long esr0,unsigned long esr14,unsigned long esr15,unsigned long msr0,unsigned long msr1)456 asmlinkage void compound_exception(unsigned long esfr1,
457 unsigned long esr0, unsigned long esr14, unsigned long esr15,
458 unsigned long msr0, unsigned long msr1)
459 {
460 die_if_kernel("-- Compound Exception --\n"
461 "ESR0 : %08lx\n"
462 "ESR15 : %08lx\n"
463 "ESR15 : %08lx\n"
464 "MSR0 : %08lx\n"
465 "MSR1 : %08lx\n",
466 esr0, esr14, esr15, msr0, msr1);
467 BUG();
468 } /* end compound_exception() */
469
470 /*****************************************************************************/
471 /*
472 * The architecture-independent backtrace generator
473 */
dump_stack(void)474 void dump_stack(void)
475 {
476 show_stack(NULL, NULL);
477 }
478
479 EXPORT_SYMBOL(dump_stack);
480
show_stack(struct task_struct * task,unsigned long * sp)481 void show_stack(struct task_struct *task, unsigned long *sp)
482 {
483 }
484
show_trace_task(struct task_struct * tsk)485 void show_trace_task(struct task_struct *tsk)
486 {
487 printk("CONTEXT: stack=0x%lx frame=0x%p LR=0x%lx RET=0x%lx\n",
488 tsk->thread.sp, tsk->thread.frame, tsk->thread.lr, tsk->thread.sched_lr);
489 }
490
491 static const char *regnames[] = {
492 "PSR ", "ISR ", "CCR ", "CCCR",
493 "LR ", "LCR ", "PC ", "_stt",
494 "sys ", "GR8*", "GNE0", "GNE1",
495 "IACH", "IACL",
496 "TBR ", "SP ", "FP ", "GR3 ",
497 "GR4 ", "GR5 ", "GR6 ", "GR7 ",
498 "GR8 ", "GR9 ", "GR10", "GR11",
499 "GR12", "GR13", "GR14", "GR15",
500 "GR16", "GR17", "GR18", "GR19",
501 "GR20", "GR21", "GR22", "GR23",
502 "GR24", "GR25", "GR26", "GR27",
503 "EFRM", "CURR", "GR30", "BFRM"
504 };
505
show_regs(struct pt_regs * regs)506 void show_regs(struct pt_regs *regs)
507 {
508 unsigned long *reg;
509 int loop;
510
511 printk("\n");
512
513 printk("Frame: @%08lx [%s]\n",
514 (unsigned long) regs,
515 regs->psr & PSR_S ? "kernel" : "user");
516
517 reg = (unsigned long *) regs;
518 for (loop = 0; loop < NR_PT_REGS; loop++) {
519 printk("%s %08lx", regnames[loop + 0], reg[loop + 0]);
520
521 if (loop == NR_PT_REGS - 1 || loop % 5 == 4)
522 printk("\n");
523 else
524 printk(" | ");
525 }
526
527 printk("Process %s (pid: %d)\n", current->comm, current->pid);
528 }
529
die_if_kernel(const char * str,...)530 void die_if_kernel(const char *str, ...)
531 {
532 char buffer[256];
533 va_list va;
534
535 if (user_mode(__frame))
536 return;
537
538 va_start(va, str);
539 vsprintf(buffer, str, va);
540 va_end(va);
541
542 console_verbose();
543 printk("\n===================================\n");
544 printk("%s\n", buffer);
545 show_backtrace(__frame, 0);
546
547 __break_hijack_kernel_event();
548 do_exit(SIGSEGV);
549 }
550
551 /*****************************************************************************/
552 /*
553 * dump the contents of an exception frame
554 */
show_backtrace_regs(struct pt_regs * frame)555 static void show_backtrace_regs(struct pt_regs *frame)
556 {
557 unsigned long *reg;
558 int loop;
559
560 /* print the registers for this frame */
561 printk("<-- %s Frame: @%p -->\n",
562 frame->psr & PSR_S ? "Kernel Mode" : "User Mode",
563 frame);
564
565 reg = (unsigned long *) frame;
566 for (loop = 0; loop < NR_PT_REGS; loop++) {
567 printk("%s %08lx", regnames[loop + 0], reg[loop + 0]);
568
569 if (loop == NR_PT_REGS - 1 || loop % 5 == 4)
570 printk("\n");
571 else
572 printk(" | ");
573 }
574
575 printk("--------\n");
576 } /* end show_backtrace_regs() */
577
578 /*****************************************************************************/
579 /*
580 * generate a backtrace of the kernel stack
581 */
show_backtrace(struct pt_regs * frame,unsigned long sp)582 void show_backtrace(struct pt_regs *frame, unsigned long sp)
583 {
584 struct pt_regs *frame0;
585 unsigned long tos = 0, stop = 0, base;
586 int format;
587
588 base = ((((unsigned long) frame) + 8191) & ~8191) - sizeof(struct user_context);
589 frame0 = (struct pt_regs *) base;
590
591 if (sp) {
592 tos = sp;
593 stop = (unsigned long) frame;
594 }
595
596 printk("\nProcess %s (pid: %d)\n\n", current->comm, current->pid);
597
598 for (;;) {
599 /* dump stack segment between frames */
600 //printk("%08lx -> %08lx\n", tos, stop);
601 format = 0;
602 while (tos < stop) {
603 if (format == 0)
604 printk(" %04lx :", tos & 0xffff);
605
606 printk(" %08lx", *(unsigned long *) tos);
607
608 tos += 4;
609 format++;
610 if (format == 8) {
611 printk("\n");
612 format = 0;
613 }
614 }
615
616 if (format > 0)
617 printk("\n");
618
619 /* dump frame 0 outside of the loop */
620 if (frame == frame0)
621 break;
622
623 tos = frame->sp;
624 if (((unsigned long) frame) + sizeof(*frame) != tos) {
625 printk("-- TOS %08lx does not follow frame %p --\n",
626 tos, frame);
627 break;
628 }
629
630 show_backtrace_regs(frame);
631
632 /* dump the stack between this frame and the next */
633 stop = (unsigned long) frame->next_frame;
634 if (stop != base &&
635 (stop < tos ||
636 stop > base ||
637 (stop < base && stop + sizeof(*frame) > base) ||
638 stop & 3)) {
639 printk("-- next_frame %08lx is invalid (range %08lx-%08lx) --\n",
640 stop, tos, base);
641 break;
642 }
643
644 /* move to next frame */
645 frame = frame->next_frame;
646 }
647
648 /* we can always dump frame 0, even if the rest of the stack is corrupt */
649 show_backtrace_regs(frame0);
650
651 } /* end show_backtrace() */
652
653 /*****************************************************************************/
654 /*
655 * initialise traps
656 */
trap_init(void)657 void __init trap_init (void)
658 {
659 } /* end trap_init() */
660