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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/arm/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/arm/kernel/traps.c')
-rw-r--r--arch/arm/kernel/traps.c590
1 files changed, 590 insertions, 0 deletions
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
new file mode 100644
index 000000000000..93dc4646cd7f
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+++ b/arch/arm/kernel/traps.c
@@ -0,0 +1,590 @@
1/*
2 * linux/arch/arm/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 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * 'traps.c' handles hardware exceptions after we have saved some state in
12 * 'linux/arch/arm/lib/traps.S'. Mostly a debugging aid, but will probably
13 * kill the offending process.
14 */
15#include <linux/config.h>
16#include <linux/module.h>
17#include <linux/signal.h>
18#include <linux/spinlock.h>
19#include <linux/personality.h>
20#include <linux/ptrace.h>
21#include <linux/kallsyms.h>
22#include <linux/init.h>
23
24#include <asm/atomic.h>
25#include <asm/cacheflush.h>
26#include <asm/io.h>
27#include <asm/system.h>
28#include <asm/uaccess.h>
29#include <asm/unistd.h>
30#include <asm/traps.h>
31
32#include "ptrace.h"
33
34extern void c_backtrace (unsigned long fp, int pmode);
35extern void show_pte(struct mm_struct *mm, unsigned long addr);
36
37const char *processor_modes[]=
38{ "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
39 "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
40 "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,
41 "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
42};
43
44static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" };
45
46#ifdef CONFIG_DEBUG_USER
47unsigned int user_debug;
48
49static int __init user_debug_setup(char *str)
50{
51 get_option(&str, &user_debug);
52 return 1;
53}
54__setup("user_debug=", user_debug_setup);
55#endif
56
57void dump_backtrace_entry(unsigned long where, unsigned long from)
58{
59#ifdef CONFIG_KALLSYMS
60 printk("[<%08lx>] ", where);
61 print_symbol("(%s) ", where);
62 printk("from [<%08lx>] ", from);
63 print_symbol("(%s)\n", from);
64#else
65 printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from);
66#endif
67}
68
69/*
70 * Stack pointers should always be within the kernels view of
71 * physical memory. If it is not there, then we can't dump
72 * out any information relating to the stack.
73 */
74static int verify_stack(unsigned long sp)
75{
76 if (sp < PAGE_OFFSET || (sp > (unsigned long)high_memory && high_memory != 0))
77 return -EFAULT;
78
79 return 0;
80}
81
82/*
83 * Dump out the contents of some memory nicely...
84 */
85static void dump_mem(const char *str, unsigned long bottom, unsigned long top)
86{
87 unsigned long p = bottom & ~31;
88 mm_segment_t fs;
89 int i;
90
91 /*
92 * We need to switch to kernel mode so that we can use __get_user
93 * to safely read from kernel space. Note that we now dump the
94 * code first, just in case the backtrace kills us.
95 */
96 fs = get_fs();
97 set_fs(KERNEL_DS);
98
99 printk("%s(0x%08lx to 0x%08lx)\n", str, bottom, top);
100
101 for (p = bottom & ~31; p < top;) {
102 printk("%04lx: ", p & 0xffff);
103
104 for (i = 0; i < 8; i++, p += 4) {
105 unsigned int val;
106
107 if (p < bottom || p >= top)
108 printk(" ");
109 else {
110 __get_user(val, (unsigned long *)p);
111 printk("%08x ", val);
112 }
113 }
114 printk ("\n");
115 }
116
117 set_fs(fs);
118}
119
120static void dump_instr(struct pt_regs *regs)
121{
122 unsigned long addr = instruction_pointer(regs);
123 const int thumb = thumb_mode(regs);
124 const int width = thumb ? 4 : 8;
125 mm_segment_t fs;
126 int i;
127
128 /*
129 * We need to switch to kernel mode so that we can use __get_user
130 * to safely read from kernel space. Note that we now dump the
131 * code first, just in case the backtrace kills us.
132 */
133 fs = get_fs();
134 set_fs(KERNEL_DS);
135
136 printk("Code: ");
137 for (i = -4; i < 1; i++) {
138 unsigned int val, bad;
139
140 if (thumb)
141 bad = __get_user(val, &((u16 *)addr)[i]);
142 else
143 bad = __get_user(val, &((u32 *)addr)[i]);
144
145 if (!bad)
146 printk(i == 0 ? "(%0*x) " : "%0*x ", width, val);
147 else {
148 printk("bad PC value.");
149 break;
150 }
151 }
152 printk("\n");
153
154 set_fs(fs);
155}
156
157static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
158{
159 unsigned int fp;
160 int ok = 1;
161
162 printk("Backtrace: ");
163 fp = regs->ARM_fp;
164 if (!fp) {
165 printk("no frame pointer");
166 ok = 0;
167 } else if (verify_stack(fp)) {
168 printk("invalid frame pointer 0x%08x", fp);
169 ok = 0;
170 } else if (fp < (unsigned long)(tsk->thread_info + 1))
171 printk("frame pointer underflow");
172 printk("\n");
173
174 if (ok)
175 c_backtrace(fp, processor_mode(regs));
176}
177
178void dump_stack(void)
179{
180#ifdef CONFIG_DEBUG_ERRORS
181 __backtrace();
182#endif
183}
184
185EXPORT_SYMBOL(dump_stack);
186
187void show_stack(struct task_struct *tsk, unsigned long *sp)
188{
189 unsigned long fp;
190
191 if (!tsk)
192 tsk = current;
193
194 if (tsk != current)
195 fp = thread_saved_fp(tsk);
196 else
197 asm("mov%? %0, fp" : "=r" (fp));
198
199 c_backtrace(fp, 0x10);
200 barrier();
201}
202
203DEFINE_SPINLOCK(die_lock);
204
205/*
206 * This function is protected against re-entrancy.
207 */
208NORET_TYPE void die(const char *str, struct pt_regs *regs, int err)
209{
210 struct task_struct *tsk = current;
211 static int die_counter;
212
213 console_verbose();
214 spin_lock_irq(&die_lock);
215 bust_spinlocks(1);
216
217 printk("Internal error: %s: %x [#%d]\n", str, err, ++die_counter);
218 print_modules();
219 printk("CPU: %d\n", smp_processor_id());
220 show_regs(regs);
221 printk("Process %s (pid: %d, stack limit = 0x%p)\n",
222 tsk->comm, tsk->pid, tsk->thread_info + 1);
223
224 if (!user_mode(regs) || in_interrupt()) {
225 dump_mem("Stack: ", regs->ARM_sp, 8192+(unsigned long)tsk->thread_info);
226 dump_backtrace(regs, tsk);
227 dump_instr(regs);
228 }
229
230 bust_spinlocks(0);
231 spin_unlock_irq(&die_lock);
232 do_exit(SIGSEGV);
233}
234
235void die_if_kernel(const char *str, struct pt_regs *regs, int err)
236{
237 if (user_mode(regs))
238 return;
239
240 die(str, regs, err);
241}
242
243static void notify_die(const char *str, struct pt_regs *regs, siginfo_t *info,
244 unsigned long err, unsigned long trap)
245{
246 if (user_mode(regs)) {
247 current->thread.error_code = err;
248 current->thread.trap_no = trap;
249
250 force_sig_info(info->si_signo, info, current);
251 } else {
252 die(str, regs, err);
253 }
254}
255
256static LIST_HEAD(undef_hook);
257static DEFINE_SPINLOCK(undef_lock);
258
259void register_undef_hook(struct undef_hook *hook)
260{
261 spin_lock_irq(&undef_lock);
262 list_add(&hook->node, &undef_hook);
263 spin_unlock_irq(&undef_lock);
264}
265
266void unregister_undef_hook(struct undef_hook *hook)
267{
268 spin_lock_irq(&undef_lock);
269 list_del(&hook->node);
270 spin_unlock_irq(&undef_lock);
271}
272
273asmlinkage void do_undefinstr(struct pt_regs *regs)
274{
275 unsigned int correction = thumb_mode(regs) ? 2 : 4;
276 unsigned int instr;
277 struct undef_hook *hook;
278 siginfo_t info;
279 void __user *pc;
280
281 /*
282 * According to the ARM ARM, PC is 2 or 4 bytes ahead,
283 * depending whether we're in Thumb mode or not.
284 * Correct this offset.
285 */
286 regs->ARM_pc -= correction;
287
288 pc = (void __user *)instruction_pointer(regs);
289 if (thumb_mode(regs)) {
290 get_user(instr, (u16 __user *)pc);
291 } else {
292 get_user(instr, (u32 __user *)pc);
293 }
294
295 spin_lock_irq(&undef_lock);
296 list_for_each_entry(hook, &undef_hook, node) {
297 if ((instr & hook->instr_mask) == hook->instr_val &&
298 (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val) {
299 if (hook->fn(regs, instr) == 0) {
300 spin_unlock_irq(&undef_lock);
301 return;
302 }
303 }
304 }
305 spin_unlock_irq(&undef_lock);
306
307#ifdef CONFIG_DEBUG_USER
308 if (user_debug & UDBG_UNDEFINED) {
309 printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n",
310 current->comm, current->pid, pc);
311 dump_instr(regs);
312 }
313#endif
314
315 info.si_signo = SIGILL;
316 info.si_errno = 0;
317 info.si_code = ILL_ILLOPC;
318 info.si_addr = pc;
319
320 notify_die("Oops - undefined instruction", regs, &info, 0, 6);
321}
322
323asmlinkage void do_unexp_fiq (struct pt_regs *regs)
324{
325#ifndef CONFIG_IGNORE_FIQ
326 printk("Hmm. Unexpected FIQ received, but trying to continue\n");
327 printk("You may have a hardware problem...\n");
328#endif
329}
330
331/*
332 * bad_mode handles the impossible case in the vectors. If you see one of
333 * these, then it's extremely serious, and could mean you have buggy hardware.
334 * It never returns, and never tries to sync. We hope that we can at least
335 * dump out some state information...
336 */
337asmlinkage void bad_mode(struct pt_regs *regs, int reason, int proc_mode)
338{
339 console_verbose();
340
341 printk(KERN_CRIT "Bad mode in %s handler detected: mode %s\n",
342 handler[reason], processor_modes[proc_mode]);
343
344 die("Oops - bad mode", regs, 0);
345 local_irq_disable();
346 panic("bad mode");
347}
348
349static int bad_syscall(int n, struct pt_regs *regs)
350{
351 struct thread_info *thread = current_thread_info();
352 siginfo_t info;
353
354 if (current->personality != PER_LINUX && thread->exec_domain->handler) {
355 thread->exec_domain->handler(n, regs);
356 return regs->ARM_r0;
357 }
358
359#ifdef CONFIG_DEBUG_USER
360 if (user_debug & UDBG_SYSCALL) {
361 printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n",
362 current->pid, current->comm, n);
363 dump_instr(regs);
364 }
365#endif
366
367 info.si_signo = SIGILL;
368 info.si_errno = 0;
369 info.si_code = ILL_ILLTRP;
370 info.si_addr = (void __user *)instruction_pointer(regs) -
371 (thumb_mode(regs) ? 2 : 4);
372
373 notify_die("Oops - bad syscall", regs, &info, n, 0);
374
375 return regs->ARM_r0;
376}
377
378static inline void
379do_cache_op(unsigned long start, unsigned long end, int flags)
380{
381 struct vm_area_struct *vma;
382
383 if (end < start || flags)
384 return;
385
386 vma = find_vma(current->active_mm, start);
387 if (vma && vma->vm_start < end) {
388 if (start < vma->vm_start)
389 start = vma->vm_start;
390 if (end > vma->vm_end)
391 end = vma->vm_end;
392
393 flush_cache_user_range(vma, start, 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 struct thread_info *thread = current_thread_info();
405 siginfo_t info;
406
407 if ((no >> 16) != 0x9f)
408 return bad_syscall(no, regs);
409
410 switch (no & 0xffff) {
411 case 0: /* branch through 0 */
412 info.si_signo = SIGSEGV;
413 info.si_errno = 0;
414 info.si_code = SEGV_MAPERR;
415 info.si_addr = NULL;
416
417 notify_die("branch through zero", regs, &info, 0, 0);
418 return 0;
419
420 case NR(breakpoint): /* SWI BREAK_POINT */
421 regs->ARM_pc -= thumb_mode(regs) ? 2 : 4;
422 ptrace_break(current, regs);
423 return regs->ARM_r0;
424
425 /*
426 * Flush a region from virtual address 'r0' to virtual address 'r1'
427 * _exclusive_. There is no alignment requirement on either address;
428 * user space does not need to know the hardware cache layout.
429 *
430 * r2 contains flags. It should ALWAYS be passed as ZERO until it
431 * is defined to be something else. For now we ignore it, but may
432 * the fires of hell burn in your belly if you break this rule. ;)
433 *
434 * (at a later date, we may want to allow this call to not flush
435 * various aspects of the cache. Passing '0' will guarantee that
436 * everything necessary gets flushed to maintain consistency in
437 * the specified region).
438 */
439 case NR(cacheflush):
440 do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2);
441 return 0;
442
443 case NR(usr26):
444 if (!(elf_hwcap & HWCAP_26BIT))
445 break;
446 regs->ARM_cpsr &= ~MODE32_BIT;
447 return regs->ARM_r0;
448
449 case NR(usr32):
450 if (!(elf_hwcap & HWCAP_26BIT))
451 break;
452 regs->ARM_cpsr |= MODE32_BIT;
453 return regs->ARM_r0;
454
455 case NR(set_tls):
456 thread->tp_value = regs->ARM_r0;
457 /*
458 * Our user accessible TLS ptr is located at 0xffff0ffc.
459 * On SMP read access to this address must raise a fault
460 * and be emulated from the data abort handler.
461 * m
462 */
463 *((unsigned long *)0xffff0ffc) = thread->tp_value;
464 return 0;
465
466 default:
467 /* Calls 9f00xx..9f07ff are defined to return -ENOSYS
468 if not implemented, rather than raising SIGILL. This
469 way the calling program can gracefully determine whether
470 a feature is supported. */
471 if (no <= 0x7ff)
472 return -ENOSYS;
473 break;
474 }
475#ifdef CONFIG_DEBUG_USER
476 /*
477 * experience shows that these seem to indicate that
478 * something catastrophic has happened
479 */
480 if (user_debug & UDBG_SYSCALL) {
481 printk("[%d] %s: arm syscall %d\n",
482 current->pid, current->comm, no);
483 dump_instr(regs);
484 if (user_mode(regs)) {
485 show_regs(regs);
486 c_backtrace(regs->ARM_fp, processor_mode(regs));
487 }
488 }
489#endif
490 info.si_signo = SIGILL;
491 info.si_errno = 0;
492 info.si_code = ILL_ILLTRP;
493 info.si_addr = (void __user *)instruction_pointer(regs) -
494 (thumb_mode(regs) ? 2 : 4);
495
496 notify_die("Oops - bad syscall(2)", regs, &info, no, 0);
497 return 0;
498}
499
500void __bad_xchg(volatile void *ptr, int size)
501{
502 printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n",
503 __builtin_return_address(0), ptr, size);
504 BUG();
505}
506EXPORT_SYMBOL(__bad_xchg);
507
508/*
509 * A data abort trap was taken, but we did not handle the instruction.
510 * Try to abort the user program, or panic if it was the kernel.
511 */
512asmlinkage void
513baddataabort(int code, unsigned long instr, struct pt_regs *regs)
514{
515 unsigned long addr = instruction_pointer(regs);
516 siginfo_t info;
517
518#ifdef CONFIG_DEBUG_USER
519 if (user_debug & UDBG_BADABORT) {
520 printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n",
521 current->pid, current->comm, code, instr);
522 dump_instr(regs);
523 show_pte(current->mm, addr);
524 }
525#endif
526
527 info.si_signo = SIGILL;
528 info.si_errno = 0;
529 info.si_code = ILL_ILLOPC;
530 info.si_addr = (void __user *)addr;
531
532 notify_die("unknown data abort code", regs, &info, instr, 0);
533}
534
535volatile void __bug(const char *file, int line, void *data)
536{
537 printk(KERN_CRIT"kernel BUG at %s:%d!", file, line);
538 if (data)
539 printk(" - extra data = %p", data);
540 printk("\n");
541 *(int *)0 = 0;
542}
543EXPORT_SYMBOL(__bug);
544
545void __readwrite_bug(const char *fn)
546{
547 printk("%s called, but not implemented\n", fn);
548 BUG();
549}
550EXPORT_SYMBOL(__readwrite_bug);
551
552void __pte_error(const char *file, int line, unsigned long val)
553{
554 printk("%s:%d: bad pte %08lx.\n", file, line, val);
555}
556
557void __pmd_error(const char *file, int line, unsigned long val)
558{
559 printk("%s:%d: bad pmd %08lx.\n", file, line, val);
560}
561
562void __pgd_error(const char *file, int line, unsigned long val)
563{
564 printk("%s:%d: bad pgd %08lx.\n", file, line, val);
565}
566
567asmlinkage void __div0(void)
568{
569 printk("Division by zero in kernel.\n");
570 dump_stack();
571}
572EXPORT_SYMBOL(__div0);
573
574void abort(void)
575{
576 BUG();
577
578 /* if that doesn't kill us, halt */
579 panic("Oops failed to kill thread");
580}
581EXPORT_SYMBOL(abort);
582
583void __init trap_init(void)
584{
585 extern void __trap_init(void);
586
587 __trap_init();
588 flush_icache_range(0xffff0000, 0xffff0000 + PAGE_SIZE);
589 modify_domain(DOMAIN_USER, DOMAIN_CLIENT);
590}