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CommitLineData
1da177e4
LT
1/*
2 * linux/arch/arm/kernel/traps.c
3 *
ab72b007 4 * Copyright (C) 1995-2009 Russell King
1da177e4
LT
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 */
1da177e4 15#include <linux/signal.h>
1da177e4 16#include <linux/personality.h>
1da177e4 17#include <linux/kallsyms.h>
a9221de6
RK
18#include <linux/spinlock.h>
19#include <linux/uaccess.h>
67306da6 20#include <linux/hardirq.h>
a9221de6
RK
21#include <linux/kdebug.h>
22#include <linux/module.h>
23#include <linux/kexec.h>
24#include <linux/delay.h>
1da177e4 25#include <linux/init.h>
425fc47a 26#include <linux/sched.h>
1da177e4
LT
27
28#include <asm/atomic.h>
29#include <asm/cacheflush.h>
1da177e4 30#include <asm/system.h>
1da177e4
LT
31#include <asm/unistd.h>
32#include <asm/traps.h>
bff595c1 33#include <asm/unwind.h>
f159f4ed 34#include <asm/tls.h>
1da177e4 35
e00d349e 36#include "signal.h"
1da177e4 37
1da177e4
LT
38static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" };
39
247055aa
CM
40void *vectors_page;
41
1da177e4
LT
42#ifdef CONFIG_DEBUG_USER
43unsigned int user_debug;
44
45static int __init user_debug_setup(char *str)
46{
47 get_option(&str, &user_debug);
48 return 1;
49}
50__setup("user_debug=", user_debug_setup);
51#endif
52
e40c2ec6 53static void dump_mem(const char *, const char *, unsigned long, unsigned long);
7ab3f8d5 54
7ab3f8d5 55void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame)
1da177e4
LT
56{
57#ifdef CONFIG_KALLSYMS
69448c2a 58 printk("[<%08lx>] (%pS) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from);
1da177e4
LT
59#else
60 printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from);
61#endif
7ab3f8d5
RK
62
63 if (in_exception_text(where))
e40c2ec6 64 dump_mem("", "Exception stack", frame + 4, frame + 4 + sizeof(struct pt_regs));
1da177e4
LT
65}
66
bff595c1 67#ifndef CONFIG_ARM_UNWIND
1da177e4
LT
68/*
69 * Stack pointers should always be within the kernels view of
70 * physical memory. If it is not there, then we can't dump
71 * out any information relating to the stack.
72 */
73static int verify_stack(unsigned long sp)
74{
09d9bae0
RK
75 if (sp < PAGE_OFFSET ||
76 (sp > (unsigned long)high_memory && high_memory != NULL))
1da177e4
LT
77 return -EFAULT;
78
79 return 0;
80}
bff595c1 81#endif
1da177e4
LT
82
83/*
84 * Dump out the contents of some memory nicely...
85 */
e40c2ec6
RK
86static void dump_mem(const char *lvl, const char *str, unsigned long bottom,
87 unsigned long top)
1da177e4 88{
d191fe09 89 unsigned long first;
1da177e4
LT
90 mm_segment_t fs;
91 int i;
92
93 /*
94 * We need to switch to kernel mode so that we can use __get_user
95 * to safely read from kernel space. Note that we now dump the
96 * code first, just in case the backtrace kills us.
97 */
98 fs = get_fs();
99 set_fs(KERNEL_DS);
100
e40c2ec6 101 printk("%s%s(0x%08lx to 0x%08lx)\n", lvl, str, bottom, top);
1da177e4 102
d191fe09
RK
103 for (first = bottom & ~31; first < top; first += 32) {
104 unsigned long p;
105 char str[sizeof(" 12345678") * 8 + 1];
1da177e4 106
d191fe09
RK
107 memset(str, ' ', sizeof(str));
108 str[sizeof(str) - 1] = '\0';
1da177e4 109
d191fe09
RK
110 for (p = first, i = 0; i < 8 && p < top; i++, p += 4) {
111 if (p >= bottom && p < top) {
112 unsigned long val;
113 if (__get_user(val, (unsigned long *)p) == 0)
114 sprintf(str + i * 9, " %08lx", val);
115 else
116 sprintf(str + i * 9, " ????????");
1da177e4
LT
117 }
118 }
e40c2ec6 119 printk("%s%04lx:%s\n", lvl, first & 0xffff, str);
1da177e4
LT
120 }
121
122 set_fs(fs);
123}
124
e40c2ec6 125static void dump_instr(const char *lvl, struct pt_regs *regs)
1da177e4
LT
126{
127 unsigned long addr = instruction_pointer(regs);
128 const int thumb = thumb_mode(regs);
129 const int width = thumb ? 4 : 8;
130 mm_segment_t fs;
d191fe09 131 char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
1da177e4
LT
132 int i;
133
134 /*
135 * We need to switch to kernel mode so that we can use __get_user
136 * to safely read from kernel space. Note that we now dump the
137 * code first, just in case the backtrace kills us.
138 */
139 fs = get_fs();
140 set_fs(KERNEL_DS);
141
1da177e4
LT
142 for (i = -4; i < 1; i++) {
143 unsigned int val, bad;
144
145 if (thumb)
146 bad = __get_user(val, &((u16 *)addr)[i]);
147 else
148 bad = __get_user(val, &((u32 *)addr)[i]);
149
150 if (!bad)
d191fe09
RK
151 p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ",
152 width, val);
1da177e4 153 else {
d191fe09 154 p += sprintf(p, "bad PC value");
1da177e4
LT
155 break;
156 }
157 }
e40c2ec6 158 printk("%sCode: %s\n", lvl, str);
1da177e4
LT
159
160 set_fs(fs);
161}
162
bff595c1
CM
163#ifdef CONFIG_ARM_UNWIND
164static inline void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
165{
166 unwind_backtrace(regs, tsk);
167}
168#else
1da177e4
LT
169static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
170{
67a94c23 171 unsigned int fp, mode;
1da177e4
LT
172 int ok = 1;
173
174 printk("Backtrace: ");
67a94c23
CM
175
176 if (!tsk)
177 tsk = current;
178
179 if (regs) {
180 fp = regs->ARM_fp;
181 mode = processor_mode(regs);
182 } else if (tsk != current) {
183 fp = thread_saved_fp(tsk);
184 mode = 0x10;
185 } else {
186 asm("mov %0, fp" : "=r" (fp) : : "cc");
187 mode = 0x10;
188 }
189
1da177e4
LT
190 if (!fp) {
191 printk("no frame pointer");
192 ok = 0;
193 } else if (verify_stack(fp)) {
194 printk("invalid frame pointer 0x%08x", fp);
195 ok = 0;
55205823 196 } else if (fp < (unsigned long)end_of_stack(tsk))
1da177e4
LT
197 printk("frame pointer underflow");
198 printk("\n");
199
200 if (ok)
67a94c23 201 c_backtrace(fp, mode);
1da177e4 202}
bff595c1 203#endif
1da177e4
LT
204
205void dump_stack(void)
206{
67a94c23 207 dump_backtrace(NULL, NULL);
1da177e4
LT
208}
209
210EXPORT_SYMBOL(dump_stack);
211
212void show_stack(struct task_struct *tsk, unsigned long *sp)
213{
67a94c23 214 dump_backtrace(NULL, tsk);
1da177e4
LT
215 barrier();
216}
217
d9202429
RK
218#ifdef CONFIG_PREEMPT
219#define S_PREEMPT " PREEMPT"
220#else
221#define S_PREEMPT ""
222#endif
223#ifdef CONFIG_SMP
224#define S_SMP " SMP"
225#else
226#define S_SMP ""
227#endif
228
a9221de6 229static int __die(const char *str, int err, struct thread_info *thread, struct pt_regs *regs)
1da177e4 230{
d362979a 231 struct task_struct *tsk = thread->task;
1da177e4 232 static int die_counter;
a9221de6 233 int ret;
1da177e4 234
e40c2ec6 235 printk(KERN_EMERG "Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n",
d9202429 236 str, err, ++die_counter);
a9221de6
RK
237
238 /* trap and error numbers are mostly meaningless on ARM */
239 ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, SIGSEGV);
240 if (ret == NOTIFY_STOP)
241 return ret;
242
1da177e4 243 print_modules();
652a12ef 244 __show_regs(regs);
e40c2ec6
RK
245 printk(KERN_EMERG "Process %.*s (pid: %d, stack limit = 0x%p)\n",
246 TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1);
1da177e4
LT
247
248 if (!user_mode(regs) || in_interrupt()) {
e40c2ec6 249 dump_mem(KERN_EMERG, "Stack: ", regs->ARM_sp,
32d39a93 250 THREAD_SIZE + (unsigned long)task_stack_page(tsk));
1da177e4 251 dump_backtrace(regs, tsk);
e40c2ec6 252 dump_instr(KERN_EMERG, regs);
1da177e4 253 }
a9221de6
RK
254
255 return ret;
d362979a 256}
1da177e4 257
2bbd7e9b 258static DEFINE_SPINLOCK(die_lock);
d362979a
RK
259
260/*
261 * This function is protected against re-entrancy.
262 */
a9221de6 263void die(const char *str, struct pt_regs *regs, int err)
d362979a
RK
264{
265 struct thread_info *thread = current_thread_info();
a9221de6 266 int ret;
d362979a 267
d9202429
RK
268 oops_enter();
269
d362979a 270 spin_lock_irq(&die_lock);
03a6e5bd 271 console_verbose();
d362979a 272 bust_spinlocks(1);
a9221de6
RK
273 ret = __die(str, err, thread, regs);
274
275 if (regs && kexec_should_crash(thread->task))
276 crash_kexec(regs);
277
1da177e4 278 bust_spinlocks(0);
bcdcd8e7 279 add_taint(TAINT_DIE);
1da177e4 280 spin_unlock_irq(&die_lock);
03a6e5bd 281 oops_exit();
31867499 282
d9202429
RK
283 if (in_interrupt())
284 panic("Fatal exception in interrupt");
cea6a4ba 285 if (panic_on_oops)
012c437d 286 panic("Fatal exception");
a9221de6
RK
287 if (ret != NOTIFY_STOP)
288 do_exit(SIGSEGV);
1da177e4
LT
289}
290
1eeb66a1
CH
291void arm_notify_die(const char *str, struct pt_regs *regs,
292 struct siginfo *info, unsigned long err, unsigned long trap)
1da177e4
LT
293{
294 if (user_mode(regs)) {
295 current->thread.error_code = err;
296 current->thread.trap_no = trap;
297
298 force_sig_info(info->si_signo, info, current);
299 } else {
300 die(str, regs, err);
301 }
302}
303
304static LIST_HEAD(undef_hook);
305static DEFINE_SPINLOCK(undef_lock);
306
307void register_undef_hook(struct undef_hook *hook)
308{
109d89ca
RK
309 unsigned long flags;
310
311 spin_lock_irqsave(&undef_lock, flags);
1da177e4 312 list_add(&hook->node, &undef_hook);
109d89ca 313 spin_unlock_irqrestore(&undef_lock, flags);
1da177e4
LT
314}
315
316void unregister_undef_hook(struct undef_hook *hook)
317{
109d89ca
RK
318 unsigned long flags;
319
320 spin_lock_irqsave(&undef_lock, flags);
1da177e4 321 list_del(&hook->node);
109d89ca 322 spin_unlock_irqrestore(&undef_lock, flags);
1da177e4
LT
323}
324
b03a5b75
RK
325static int call_undef_hook(struct pt_regs *regs, unsigned int instr)
326{
327 struct undef_hook *hook;
328 unsigned long flags;
329 int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL;
330
331 spin_lock_irqsave(&undef_lock, flags);
332 list_for_each_entry(hook, &undef_hook, node)
333 if ((instr & hook->instr_mask) == hook->instr_val &&
334 (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val)
335 fn = hook->fn;
336 spin_unlock_irqrestore(&undef_lock, flags);
337
338 return fn ? fn(regs, instr) : 1;
339}
340
7ab3f8d5 341asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
1da177e4
LT
342{
343 unsigned int correction = thumb_mode(regs) ? 2 : 4;
344 unsigned int instr;
1da177e4
LT
345 siginfo_t info;
346 void __user *pc;
347
348 /*
349 * According to the ARM ARM, PC is 2 or 4 bytes ahead,
350 * depending whether we're in Thumb mode or not.
351 * Correct this offset.
352 */
353 regs->ARM_pc -= correction;
354
355 pc = (void __user *)instruction_pointer(regs);
dfc544c7
DW
356
357 if (processor_mode(regs) == SVC_MODE) {
358 instr = *(u32 *) pc;
359 } else if (thumb_mode(regs)) {
1da177e4
LT
360 get_user(instr, (u16 __user *)pc);
361 } else {
362 get_user(instr, (u32 __user *)pc);
363 }
364
b03a5b75
RK
365 if (call_undef_hook(regs, instr) == 0)
366 return;
1da177e4
LT
367
368#ifdef CONFIG_DEBUG_USER
369 if (user_debug & UDBG_UNDEFINED) {
370 printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n",
19c5870c 371 current->comm, task_pid_nr(current), pc);
e40c2ec6 372 dump_instr(KERN_INFO, regs);
1da177e4
LT
373 }
374#endif
375
376 info.si_signo = SIGILL;
377 info.si_errno = 0;
378 info.si_code = ILL_ILLOPC;
379 info.si_addr = pc;
380
1eeb66a1 381 arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6);
1da177e4
LT
382}
383
384asmlinkage void do_unexp_fiq (struct pt_regs *regs)
385{
1da177e4
LT
386 printk("Hmm. Unexpected FIQ received, but trying to continue\n");
387 printk("You may have a hardware problem...\n");
1da177e4
LT
388}
389
390/*
391 * bad_mode handles the impossible case in the vectors. If you see one of
392 * these, then it's extremely serious, and could mean you have buggy hardware.
393 * It never returns, and never tries to sync. We hope that we can at least
394 * dump out some state information...
395 */
ae0a846e 396asmlinkage void bad_mode(struct pt_regs *regs, int reason)
1da177e4
LT
397{
398 console_verbose();
399
ae0a846e 400 printk(KERN_CRIT "Bad mode in %s handler detected\n", handler[reason]);
1da177e4
LT
401
402 die("Oops - bad mode", regs, 0);
403 local_irq_disable();
404 panic("bad mode");
405}
406
407static int bad_syscall(int n, struct pt_regs *regs)
408{
409 struct thread_info *thread = current_thread_info();
410 siginfo_t info;
411
88b9ef45 412 if ((current->personality & PER_MASK) != PER_LINUX &&
a999cb04 413 thread->exec_domain->handler) {
1da177e4
LT
414 thread->exec_domain->handler(n, regs);
415 return regs->ARM_r0;
416 }
417
418#ifdef CONFIG_DEBUG_USER
419 if (user_debug & UDBG_SYSCALL) {
420 printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n",
19c5870c 421 task_pid_nr(current), current->comm, n);
e40c2ec6 422 dump_instr(KERN_ERR, regs);
1da177e4
LT
423 }
424#endif
425
426 info.si_signo = SIGILL;
427 info.si_errno = 0;
428 info.si_code = ILL_ILLTRP;
429 info.si_addr = (void __user *)instruction_pointer(regs) -
430 (thumb_mode(regs) ? 2 : 4);
431
1eeb66a1 432 arm_notify_die("Oops - bad syscall", regs, &info, n, 0);
1da177e4
LT
433
434 return regs->ARM_r0;
435}
436
437static inline void
438do_cache_op(unsigned long start, unsigned long end, int flags)
439{
aa45ee8f 440 struct mm_struct *mm = current->active_mm;
1da177e4
LT
441 struct vm_area_struct *vma;
442
443 if (end < start || flags)
444 return;
445
aa45ee8f
RK
446 down_read(&mm->mmap_sem);
447 vma = find_vma(mm, start);
1da177e4
LT
448 if (vma && vma->vm_start < end) {
449 if (start < vma->vm_start)
450 start = vma->vm_start;
451 if (end > vma->vm_end)
452 end = vma->vm_end;
453
454 flush_cache_user_range(vma, start, end);
455 }
aa45ee8f 456 up_read(&mm->mmap_sem);
1da177e4
LT
457}
458
459/*
460 * Handle all unrecognised system calls.
461 * 0x9f0000 - 0x9fffff are some more esoteric system calls
462 */
463#define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE)
464asmlinkage int arm_syscall(int no, struct pt_regs *regs)
465{
466 struct thread_info *thread = current_thread_info();
467 siginfo_t info;
468
3f2829a3 469 if ((no >> 16) != (__ARM_NR_BASE>> 16))
1da177e4
LT
470 return bad_syscall(no, regs);
471
472 switch (no & 0xffff) {
473 case 0: /* branch through 0 */
474 info.si_signo = SIGSEGV;
475 info.si_errno = 0;
476 info.si_code = SEGV_MAPERR;
477 info.si_addr = NULL;
478
1eeb66a1 479 arm_notify_die("branch through zero", regs, &info, 0, 0);
1da177e4
LT
480 return 0;
481
482 case NR(breakpoint): /* SWI BREAK_POINT */
483 regs->ARM_pc -= thumb_mode(regs) ? 2 : 4;
484 ptrace_break(current, regs);
485 return regs->ARM_r0;
486
487 /*
488 * Flush a region from virtual address 'r0' to virtual address 'r1'
489 * _exclusive_. There is no alignment requirement on either address;
490 * user space does not need to know the hardware cache layout.
491 *
492 * r2 contains flags. It should ALWAYS be passed as ZERO until it
493 * is defined to be something else. For now we ignore it, but may
494 * the fires of hell burn in your belly if you break this rule. ;)
495 *
496 * (at a later date, we may want to allow this call to not flush
497 * various aspects of the cache. Passing '0' will guarantee that
498 * everything necessary gets flushed to maintain consistency in
499 * the specified region).
500 */
501 case NR(cacheflush):
502 do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2);
503 return 0;
504
505 case NR(usr26):
506 if (!(elf_hwcap & HWCAP_26BIT))
507 break;
508 regs->ARM_cpsr &= ~MODE32_BIT;
509 return regs->ARM_r0;
510
511 case NR(usr32):
512 if (!(elf_hwcap & HWCAP_26BIT))
513 break;
514 regs->ARM_cpsr |= MODE32_BIT;
515 return regs->ARM_r0;
516
517 case NR(set_tls):
518 thread->tp_value = regs->ARM_r0;
f159f4ed
TL
519 if (tls_emu)
520 return 0;
521 if (has_tls_reg) {
522 asm ("mcr p15, 0, %0, c13, c0, 3"
523 : : "r" (regs->ARM_r0));
524 } else {
525 /*
526 * User space must never try to access this directly.
527 * Expect your app to break eventually if you do so.
528 * The user helper at 0xffff0fe0 must be used instead.
529 * (see entry-armv.S for details)
530 */
531 *((unsigned int *)0xffff0ff0) = regs->ARM_r0;
532 }
1da177e4
LT
533 return 0;
534
dcef1f63
NP
535#ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG
536 /*
537 * Atomically store r1 in *r2 if *r2 is equal to r0 for user space.
538 * Return zero in r0 if *MEM was changed or non-zero if no exchange
539 * happened. Also set the user C flag accordingly.
540 * If access permissions have to be fixed up then non-zero is
541 * returned and the operation has to be re-attempted.
542 *
543 * *NOTE*: This is a ghost syscall private to the kernel. Only the
544 * __kuser_cmpxchg code in entry-armv.S should be aware of its
545 * existence. Don't ever use this from user code.
546 */
cc20d429 547 case NR(cmpxchg):
b49c0f24 548 for (;;) {
dcef1f63
NP
549 extern void do_DataAbort(unsigned long addr, unsigned int fsr,
550 struct pt_regs *regs);
551 unsigned long val;
552 unsigned long addr = regs->ARM_r2;
553 struct mm_struct *mm = current->mm;
554 pgd_t *pgd; pmd_t *pmd; pte_t *pte;
69b04754 555 spinlock_t *ptl;
dcef1f63
NP
556
557 regs->ARM_cpsr &= ~PSR_C_BIT;
69b04754 558 down_read(&mm->mmap_sem);
dcef1f63
NP
559 pgd = pgd_offset(mm, addr);
560 if (!pgd_present(*pgd))
561 goto bad_access;
562 pmd = pmd_offset(pgd, addr);
563 if (!pmd_present(*pmd))
564 goto bad_access;
69b04754 565 pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
373ce302 566 if (!pte_present(*pte) || !pte_write(*pte) || !pte_dirty(*pte)) {
69b04754 567 pte_unmap_unlock(pte, ptl);
dcef1f63 568 goto bad_access;
69b04754 569 }
dcef1f63
NP
570 val = *(unsigned long *)addr;
571 val -= regs->ARM_r0;
572 if (val == 0) {
573 *(unsigned long *)addr = regs->ARM_r1;
574 regs->ARM_cpsr |= PSR_C_BIT;
575 }
69b04754
HD
576 pte_unmap_unlock(pte, ptl);
577 up_read(&mm->mmap_sem);
dcef1f63
NP
578 return val;
579
580 bad_access:
69b04754 581 up_read(&mm->mmap_sem);
74f88494 582 /* simulate a write access fault */
dcef1f63 583 do_DataAbort(addr, 15 + (1 << 11), regs);
dcef1f63
NP
584 }
585#endif
586
1da177e4
LT
587 default:
588 /* Calls 9f00xx..9f07ff are defined to return -ENOSYS
589 if not implemented, rather than raising SIGILL. This
590 way the calling program can gracefully determine whether
591 a feature is supported. */
bfd2e29f 592 if ((no & 0xffff) <= 0x7ff)
1da177e4
LT
593 return -ENOSYS;
594 break;
595 }
596#ifdef CONFIG_DEBUG_USER
597 /*
598 * experience shows that these seem to indicate that
599 * something catastrophic has happened
600 */
601 if (user_debug & UDBG_SYSCALL) {
602 printk("[%d] %s: arm syscall %d\n",
19c5870c 603 task_pid_nr(current), current->comm, no);
e40c2ec6 604 dump_instr("", regs);
1da177e4 605 if (user_mode(regs)) {
652a12ef 606 __show_regs(regs);
1da177e4
LT
607 c_backtrace(regs->ARM_fp, processor_mode(regs));
608 }
609 }
610#endif
611 info.si_signo = SIGILL;
612 info.si_errno = 0;
613 info.si_code = ILL_ILLTRP;
614 info.si_addr = (void __user *)instruction_pointer(regs) -
615 (thumb_mode(regs) ? 2 : 4);
616
1eeb66a1 617 arm_notify_die("Oops - bad syscall(2)", regs, &info, no, 0);
1da177e4
LT
618 return 0;
619}
620
4b0e07a5 621#ifdef CONFIG_TLS_REG_EMUL
2d2669b6
NP
622
623/*
624 * We might be running on an ARMv6+ processor which should have the TLS
4b0e07a5
NP
625 * register but for some reason we can't use it, or maybe an SMP system
626 * using a pre-ARMv6 processor (there are apparently a few prototypes like
627 * that in existence) and therefore access to that register must be
628 * emulated.
2d2669b6
NP
629 */
630
631static int get_tp_trap(struct pt_regs *regs, unsigned int instr)
632{
633 int reg = (instr >> 12) & 15;
634 if (reg == 15)
635 return 1;
636 regs->uregs[reg] = current_thread_info()->tp_value;
637 regs->ARM_pc += 4;
638 return 0;
639}
640
641static struct undef_hook arm_mrc_hook = {
642 .instr_mask = 0x0fff0fff,
643 .instr_val = 0x0e1d0f70,
644 .cpsr_mask = PSR_T_BIT,
645 .cpsr_val = 0,
646 .fn = get_tp_trap,
647};
648
649static int __init arm_mrc_hook_init(void)
650{
651 register_undef_hook(&arm_mrc_hook);
652 return 0;
653}
654
655late_initcall(arm_mrc_hook_init);
656
657#endif
658
1da177e4
LT
659void __bad_xchg(volatile void *ptr, int size)
660{
661 printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n",
662 __builtin_return_address(0), ptr, size);
663 BUG();
664}
665EXPORT_SYMBOL(__bad_xchg);
666
667/*
668 * A data abort trap was taken, but we did not handle the instruction.
669 * Try to abort the user program, or panic if it was the kernel.
670 */
671asmlinkage void
672baddataabort(int code, unsigned long instr, struct pt_regs *regs)
673{
674 unsigned long addr = instruction_pointer(regs);
675 siginfo_t info;
676
677#ifdef CONFIG_DEBUG_USER
678 if (user_debug & UDBG_BADABORT) {
679 printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n",
19c5870c 680 task_pid_nr(current), current->comm, code, instr);
e40c2ec6 681 dump_instr(KERN_ERR, regs);
1da177e4
LT
682 show_pte(current->mm, addr);
683 }
684#endif
685
686 info.si_signo = SIGILL;
687 info.si_errno = 0;
688 info.si_code = ILL_ILLOPC;
689 info.si_addr = (void __user *)addr;
690
1eeb66a1 691 arm_notify_die("unknown data abort code", regs, &info, instr, 0);
1da177e4
LT
692}
693
7174d852 694void __attribute__((noreturn)) __bug(const char *file, int line)
1da177e4 695{
7174d852 696 printk(KERN_CRIT"kernel BUG at %s:%d!\n", file, line);
1da177e4 697 *(int *)0 = 0;
6a1ced59
CM
698
699 /* Avoid "noreturn function does return" */
700 for (;;);
1da177e4
LT
701}
702EXPORT_SYMBOL(__bug);
703
704void __readwrite_bug(const char *fn)
705{
706 printk("%s called, but not implemented\n", fn);
707 BUG();
708}
709EXPORT_SYMBOL(__readwrite_bug);
710
69529c0e 711void __pte_error(const char *file, int line, pte_t pte)
1da177e4 712{
29a38193 713 printk("%s:%d: bad pte %08llx.\n", file, line, (long long)pte_val(pte));
1da177e4
LT
714}
715
69529c0e 716void __pmd_error(const char *file, int line, pmd_t pmd)
1da177e4 717{
29a38193 718 printk("%s:%d: bad pmd %08llx.\n", file, line, (long long)pmd_val(pmd));
1da177e4
LT
719}
720
69529c0e 721void __pgd_error(const char *file, int line, pgd_t pgd)
1da177e4 722{
29a38193 723 printk("%s:%d: bad pgd %08llx.\n", file, line, (long long)pgd_val(pgd));
1da177e4
LT
724}
725
726asmlinkage void __div0(void)
727{
728 printk("Division by zero in kernel.\n");
729 dump_stack();
730}
731EXPORT_SYMBOL(__div0);
732
733void abort(void)
734{
735 BUG();
736
737 /* if that doesn't kill us, halt */
738 panic("Oops failed to kill thread");
739}
740EXPORT_SYMBOL(abort);
741
742void __init trap_init(void)
5cbad0eb
JW
743{
744 return;
745}
746
f159f4ed
TL
747static void __init kuser_get_tls_init(unsigned long vectors)
748{
749 /*
750 * vectors + 0xfe0 = __kuser_get_tls
751 * vectors + 0xfe8 = hardware TLS instruction at 0xffff0fe8
752 */
753 if (tls_emu || has_tls_reg)
754 memcpy((void *)vectors + 0xfe0, (void *)vectors + 0xfe8, 4);
755}
756
5cbad0eb 757void __init early_trap_init(void)
1da177e4 758{
247055aa 759#if defined(CONFIG_CPU_USE_DOMAINS)
c760fc19 760 unsigned long vectors = CONFIG_VECTORS_BASE;
247055aa
CM
761#else
762 unsigned long vectors = (unsigned long)vectors_page;
763#endif
7933523d
RK
764 extern char __stubs_start[], __stubs_end[];
765 extern char __vectors_start[], __vectors_end[];
2d2669b6
NP
766 extern char __kuser_helper_start[], __kuser_helper_end[];
767 int kuser_sz = __kuser_helper_end - __kuser_helper_start;
1da177e4 768
7933523d 769 /*
2d2669b6
NP
770 * Copy the vectors, stubs and kuser helpers (in entry-armv.S)
771 * into the vector page, mapped at 0xffff0000, and ensure these
772 * are visible to the instruction stream.
7933523d 773 */
c760fc19
HC
774 memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start);
775 memcpy((void *)vectors + 0x200, __stubs_start, __stubs_end - __stubs_start);
776 memcpy((void *)vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz);
e00d349e 777
f159f4ed
TL
778 /*
779 * Do processor specific fixups for the kuser helpers
780 */
781 kuser_get_tls_init(vectors);
782
e00d349e
RK
783 /*
784 * Copy signal return handlers into the vector page, and
785 * set sigreturn to be a pointer to these.
786 */
247055aa
CM
787 memcpy((void *)(vectors + KERN_SIGRETURN_CODE - CONFIG_VECTORS_BASE),
788 sigreturn_codes, sizeof(sigreturn_codes));
789 memcpy((void *)(vectors + KERN_RESTART_CODE - CONFIG_VECTORS_BASE),
790 syscall_restart_code, sizeof(syscall_restart_code));
e00d349e 791
c760fc19 792 flush_icache_range(vectors, vectors + PAGE_SIZE);
1da177e4
LT
793 modify_domain(DOMAIN_USER, DOMAIN_CLIENT);
794}