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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/arm26/kernel/traps.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/arm26/kernel/traps.c')
-rw-r--r--arch/arm26/kernel/traps.c548
1 files changed, 548 insertions, 0 deletions
diff --git a/arch/arm26/kernel/traps.c b/arch/arm26/kernel/traps.c
new file mode 100644
index 000000000000..f64f59022392
--- /dev/null
+++ b/arch/arm26/kernel/traps.c
@@ -0,0 +1,548 @@
1/*
2 * linux/arch/arm26/kernel/traps.c
3 *
4 * Copyright (C) 1995-2002 Russell King
5 * Fragments that appear the same as linux/arch/i386/kernel/traps.c (C) Linus Torvalds
6 * Copyright (C) 2003 Ian Molton (ARM26)
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * 'traps.c' handles hardware exceptions after we have saved some state in
13 * 'linux/arch/arm26/lib/traps.S'. Mostly a debugging aid, but will probably
14 * kill the offending process.
15 */
16
17#include <linux/module.h>
18#include <linux/config.h>
19#include <linux/types.h>
20#include <linux/kernel.h>
21#include <linux/signal.h>
22#include <linux/sched.h>
23#include <linux/mm.h>
24#include <linux/spinlock.h>
25#include <linux/personality.h>
26#include <linux/ptrace.h>
27#include <linux/elf.h>
28#include <linux/interrupt.h>
29#include <linux/init.h>
30
31#include <asm/atomic.h>
32#include <asm/io.h>
33#include <asm/pgtable.h>
34#include <asm/system.h>
35#include <asm/uaccess.h>
36#include <asm/unistd.h>
37#include <asm/semaphore.h>
38
39#include "ptrace.h"
40
41extern void c_backtrace (unsigned long fp, int pmode);
42extern void show_pte(struct mm_struct *mm, unsigned long addr);
43
44const char *processor_modes[] = { "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" };
45
46static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" "*bad reason*"};
47
48/*
49 * Stack pointers should always be within the kernels view of
50 * physical memory. If it is not there, then we can't dump
51 * out any information relating to the stack.
52 */
53static int verify_stack(unsigned long sp)
54{
55 if (sp < PAGE_OFFSET || (sp > (unsigned long)high_memory && high_memory != 0))
56 return -EFAULT;
57
58 return 0;
59}
60
61/*
62 * Dump out the contents of some memory nicely...
63 */
64static void dump_mem(const char *str, unsigned long bottom, unsigned long top)
65{
66 unsigned long p = bottom & ~31;
67 mm_segment_t fs;
68 int i;
69
70 /*
71 * We need to switch to kernel mode so that we can use __get_user
72 * to safely read from kernel space. Note that we now dump the
73 * code first, just in case the backtrace kills us.
74 */
75 fs = get_fs();
76 set_fs(KERNEL_DS);
77
78 printk("%s", str);
79 printk("(0x%08lx to 0x%08lx)\n", bottom, top);
80
81 for (p = bottom & ~31; p < top;) {
82 printk("%04lx: ", p & 0xffff);
83
84 for (i = 0; i < 8; i++, p += 4) {
85 unsigned int val;
86
87 if (p < bottom || p >= top)
88 printk(" ");
89 else {
90 __get_user(val, (unsigned long *)p);
91 printk("%08x ", val);
92 }
93 }
94 printk ("\n");
95 }
96
97 set_fs(fs);
98}
99
100static void dump_instr(struct pt_regs *regs)
101{
102 unsigned long addr = instruction_pointer(regs);
103 const int width = 8;
104 mm_segment_t fs;
105 int i;
106
107 /*
108 * We need to switch to kernel mode so that we can use __get_user
109 * to safely read from kernel space. Note that we now dump the
110 * code first, just in case the backtrace kills us.
111 */
112 fs = get_fs();
113 set_fs(KERNEL_DS);
114
115 printk("Code: ");
116 for (i = -4; i < 1; i++) {
117 unsigned int val, bad;
118
119 bad = __get_user(val, &((u32 *)addr)[i]);
120
121 if (!bad)
122 printk(i == 0 ? "(%0*x) " : "%0*x ", width, val);
123 else {
124 printk("bad PC value.");
125 break;
126 }
127 }
128 printk("\n");
129
130 set_fs(fs);
131}
132
133/*static*/ void __dump_stack(struct task_struct *tsk, unsigned long sp)
134{
135 dump_mem("Stack: ", sp, 8192+(unsigned long)tsk->thread_info);
136}
137
138void dump_stack(void)
139{
140#ifdef CONFIG_DEBUG_ERRORS
141 __backtrace();
142#endif
143}
144
145EXPORT_SYMBOL(dump_stack);
146
147//FIXME - was a static fn
148void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
149{
150 unsigned int fp;
151 int ok = 1;
152
153 printk("Backtrace: ");
154 fp = regs->ARM_fp;
155 if (!fp) {
156 printk("no frame pointer");
157 ok = 0;
158 } else if (verify_stack(fp)) {
159 printk("invalid frame pointer 0x%08x", fp);
160 ok = 0;
161 } else if (fp < (unsigned long)(tsk->thread_info + 1))
162 printk("frame pointer underflow");
163 printk("\n");
164
165 if (ok)
166 c_backtrace(fp, processor_mode(regs));
167}
168
169/* FIXME - this is probably wrong.. */
170void show_stack(struct task_struct *task, unsigned long *sp) {
171 dump_mem("Stack: ", (unsigned long)sp, 8192+(unsigned long)task->thread_info);
172}
173
174DEFINE_SPINLOCK(die_lock);
175
176/*
177 * This function is protected against re-entrancy.
178 */
179NORET_TYPE void die(const char *str, struct pt_regs *regs, int err)
180{
181 struct task_struct *tsk = current;
182
183 console_verbose();
184 spin_lock_irq(&die_lock);
185
186 printk("Internal error: %s: %x\n", str, err);
187 printk("CPU: %d\n", smp_processor_id());
188 show_regs(regs);
189 printk("Process %s (pid: %d, stack limit = 0x%p)\n",
190 current->comm, current->pid, tsk->thread_info + 1);
191
192 if (!user_mode(regs) || in_interrupt()) {
193 __dump_stack(tsk, (unsigned long)(regs + 1));
194 dump_backtrace(regs, tsk);
195 dump_instr(regs);
196 }
197while(1);
198 spin_unlock_irq(&die_lock);
199 do_exit(SIGSEGV);
200}
201
202void die_if_kernel(const char *str, struct pt_regs *regs, int err)
203{
204 if (user_mode(regs))
205 return;
206
207 die(str, regs, err);
208}
209
210static DECLARE_MUTEX(undef_sem);
211static int (*undef_hook)(struct pt_regs *);
212
213int request_undef_hook(int (*fn)(struct pt_regs *))
214{
215 int ret = -EBUSY;
216
217 down(&undef_sem);
218 if (undef_hook == NULL) {
219 undef_hook = fn;
220 ret = 0;
221 }
222 up(&undef_sem);
223
224 return ret;
225}
226
227int release_undef_hook(int (*fn)(struct pt_regs *))
228{
229 int ret = -EINVAL;
230
231 down(&undef_sem);
232 if (undef_hook == fn) {
233 undef_hook = NULL;
234 ret = 0;
235 }
236 up(&undef_sem);
237
238 return ret;
239}
240
241static int undefined_extension(struct pt_regs *regs, unsigned int op)
242{
243 switch (op) {
244 case 1: /* 0xde01 / 0x?7f001f0 */
245 ptrace_break(current, regs);
246 return 0;
247 }
248 return 1;
249}
250
251asmlinkage void do_undefinstr(struct pt_regs *regs)
252{
253 siginfo_t info;
254 void *pc;
255
256 regs->ARM_pc -= 4;
257
258 pc = (unsigned long *)instruction_pointer(regs); /* strip PSR */
259
260 if (user_mode(regs)) {
261 u32 instr;
262
263 get_user(instr, (u32 *)pc);
264
265 if ((instr & 0x0fff00ff) == 0x07f000f0 &&
266 undefined_extension(regs, (instr >> 8) & 255) == 0) {
267 regs->ARM_pc += 4;
268 return;
269 }
270 } else {
271 if (undef_hook && undef_hook(regs) == 0) {
272 regs->ARM_pc += 4;
273 return;
274 }
275 }
276
277#ifdef CONFIG_DEBUG_USER
278 printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n",
279 current->comm, current->pid, pc);
280 dump_instr(regs);
281#endif
282
283 current->thread.error_code = 0;
284 current->thread.trap_no = 6;
285
286 info.si_signo = SIGILL;
287 info.si_errno = 0;
288 info.si_code = ILL_ILLOPC;
289 info.si_addr = pc;
290
291 force_sig_info(SIGILL, &info, current);
292
293 die_if_kernel("Oops - undefined instruction", regs, 0);
294}
295
296asmlinkage void do_excpt(unsigned long address, struct pt_regs *regs, int mode)
297{
298 siginfo_t info;
299
300#ifdef CONFIG_DEBUG_USER
301 printk(KERN_INFO "%s (%d): address exception: pc=%08lx\n",
302 current->comm, current->pid, instruction_pointer(regs));
303 dump_instr(regs);
304#endif
305
306 current->thread.error_code = 0;
307 current->thread.trap_no = 11;
308
309 info.si_signo = SIGBUS;
310 info.si_errno = 0;
311 info.si_code = BUS_ADRERR;
312 info.si_addr = (void *)address;
313
314 force_sig_info(SIGBUS, &info, current);
315
316 die_if_kernel("Oops - address exception", regs, mode);
317}
318
319asmlinkage void do_unexp_fiq (struct pt_regs *regs)
320{
321#ifndef CONFIG_IGNORE_FIQ
322 printk("Hmm. Unexpected FIQ received, but trying to continue\n");
323 printk("You may have a hardware problem...\n");
324#endif
325}
326
327/*
328 * bad_mode handles the impossible case in the vectors. If you see one of
329 * these, then it's extremely serious, and could mean you have buggy hardware.
330 * It never returns, and never tries to sync. We hope that we can at least
331 * dump out some state information...
332 */
333asmlinkage void bad_mode(struct pt_regs *regs, int reason, int proc_mode)
334{
335 unsigned int vectors = vectors_base();
336
337 console_verbose();
338
339 printk(KERN_CRIT "Bad mode in %s handler detected: mode %s\n",
340 handler[reason<5?reason:4], processor_modes[proc_mode]);
341
342 /*
343 * Dump out the vectors and stub routines. Maybe a better solution
344 * would be to dump them out only if we detect that they are corrupted.
345 */
346 dump_mem(KERN_CRIT "Vectors: ", vectors, vectors + 0x40);
347 dump_mem(KERN_CRIT "Stubs: ", vectors + 0x200, vectors + 0x4b8);
348
349 die("Oops", regs, 0);
350 local_irq_disable();
351 panic("bad mode");
352}
353
354static int bad_syscall(int n, struct pt_regs *regs)
355{
356 struct thread_info *thread = current_thread_info();
357 siginfo_t info;
358
359 if (current->personality != PER_LINUX && thread->exec_domain->handler) {
360 thread->exec_domain->handler(n, regs);
361 return regs->ARM_r0;
362 }
363
364#ifdef CONFIG_DEBUG_USER
365 printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n",
366 current->pid, current->comm, n);
367 dump_instr(regs);
368#endif
369
370 info.si_signo = SIGILL;
371 info.si_errno = 0;
372 info.si_code = ILL_ILLTRP;
373 info.si_addr = (void *)instruction_pointer(regs) - 4;
374
375 force_sig_info(SIGILL, &info, current);
376 die_if_kernel("Oops", regs, n);
377 return regs->ARM_r0;
378}
379
380static inline void
381do_cache_op(unsigned long start, unsigned long end, int flags)
382{
383 struct vm_area_struct *vma;
384
385 if (end < start)
386 return;
387
388 vma = find_vma(current->active_mm, start);
389 if (vma && vma->vm_start < end) {
390 if (start < vma->vm_start)
391 start = vma->vm_start;
392 if (end > vma->vm_end)
393 end = vma->vm_end;
394 }
395}
396
397/*
398 * Handle all unrecognised system calls.
399 * 0x9f0000 - 0x9fffff are some more esoteric system calls
400 */
401#define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE)
402asmlinkage int arm_syscall(int no, struct pt_regs *regs)
403{
404 siginfo_t info;
405
406 if ((no >> 16) != 0x9f)
407 return bad_syscall(no, regs);
408
409 switch (no & 0xffff) {
410 case 0: /* branch through 0 */
411 info.si_signo = SIGSEGV;
412 info.si_errno = 0;
413 info.si_code = SEGV_MAPERR;
414 info.si_addr = NULL;
415
416 force_sig_info(SIGSEGV, &info, current);
417
418 die_if_kernel("branch through zero", regs, 0);
419 return 0;
420
421 case NR(breakpoint): /* SWI BREAK_POINT */
422 ptrace_break(current, regs);
423 return regs->ARM_r0;
424
425 case NR(cacheflush):
426 return 0;
427
428 case NR(usr26):
429 break;
430
431 default:
432 /* Calls 9f00xx..9f07ff are defined to return -ENOSYS
433 if not implemented, rather than raising SIGILL. This
434 way the calling program can gracefully determine whether
435 a feature is supported. */
436 if (no <= 0x7ff)
437 return -ENOSYS;
438 break;
439 }
440#ifdef CONFIG_DEBUG_USER
441 /*
442 * experience shows that these seem to indicate that
443 * something catastrophic has happened
444 */
445 printk("[%d] %s: arm syscall %d\n", current->pid, current->comm, no);
446 dump_instr(regs);
447 if (user_mode(regs)) {
448 show_regs(regs);
449 c_backtrace(regs->ARM_fp, processor_mode(regs));
450 }
451#endif
452 info.si_signo = SIGILL;
453 info.si_errno = 0;
454 info.si_code = ILL_ILLTRP;
455 info.si_addr = (void *)instruction_pointer(regs) - 4;
456
457 force_sig_info(SIGILL, &info, current);
458 die_if_kernel("Oops", regs, no);
459 return 0;
460}
461
462void __bad_xchg(volatile void *ptr, int size)
463{
464 printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n",
465 __builtin_return_address(0), ptr, size);
466 BUG();
467}
468
469/*
470 * A data abort trap was taken, but we did not handle the instruction.
471 * Try to abort the user program, or panic if it was the kernel.
472 */
473asmlinkage void
474baddataabort(int code, unsigned long instr, struct pt_regs *regs)
475{
476 unsigned long addr = instruction_pointer(regs);
477 siginfo_t info;
478
479#ifdef CONFIG_DEBUG_USER
480 printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n",
481 current->pid, current->comm, code, instr);
482 dump_instr(regs);
483 show_pte(current->mm, addr);
484#endif
485
486 info.si_signo = SIGILL;
487 info.si_errno = 0;
488 info.si_code = ILL_ILLOPC;
489 info.si_addr = (void *)addr;
490
491 force_sig_info(SIGILL, &info, current);
492 die_if_kernel("unknown data abort code", regs, instr);
493}
494
495volatile void __bug(const char *file, int line, void *data)
496{
497 printk(KERN_CRIT"kernel BUG at %s:%d!", file, line);
498 if (data)
499 printk(KERN_CRIT" - extra data = %p", data);
500 printk("\n");
501 *(int *)0 = 0;
502}
503
504void __readwrite_bug(const char *fn)
505{
506 printk("%s called, but not implemented", fn);
507 BUG();
508}
509
510void __pte_error(const char *file, int line, unsigned long val)
511{
512 printk("%s:%d: bad pte %08lx.\n", file, line, val);
513}
514
515void __pmd_error(const char *file, int line, unsigned long val)
516{
517 printk("%s:%d: bad pmd %08lx.\n", file, line, val);
518}
519
520void __pgd_error(const char *file, int line, unsigned long val)
521{
522 printk("%s:%d: bad pgd %08lx.\n", file, line, val);
523}
524
525asmlinkage void __div0(void)
526{
527 printk("Division by zero in kernel.\n");
528 dump_stack();
529}
530
531void abort(void)
532{
533 BUG();
534
535 /* if that doesn't kill us, halt */
536 panic("Oops failed to kill thread");
537}
538
539void __init trap_init(void)
540{
541 extern void __trap_init(unsigned long);
542 unsigned long base = vectors_base();
543
544 __trap_init(base);
545 if (base != 0)
546 printk(KERN_DEBUG "Relocating machine vectors to 0x%08lx\n",
547 base);
548}