x86/efi: Enforce CONFIG_RELOCATABLE for EFI boot stub
[linux/fpc-iii.git] / arch / arm / kernel / traps.c
blob1f735aafd5ec96cf2e5c56d06fca3d016960e409
1 /*
2 * linux/arch/arm/kernel/traps.c
4 * Copyright (C) 1995-2009 Russell King
5 * Fragments that appear the same as linux/arch/i386/kernel/traps.c (C) Linus Torvalds
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.
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.
15 #include <linux/signal.h>
16 #include <linux/personality.h>
17 #include <linux/kallsyms.h>
18 #include <linux/spinlock.h>
19 #include <linux/uaccess.h>
20 #include <linux/hardirq.h>
21 #include <linux/kdebug.h>
22 #include <linux/module.h>
23 #include <linux/kexec.h>
24 #include <linux/bug.h>
25 #include <linux/delay.h>
26 #include <linux/init.h>
27 #include <linux/sched.h>
29 #include <linux/atomic.h>
30 #include <asm/cacheflush.h>
31 #include <asm/exception.h>
32 #include <asm/unistd.h>
33 #include <asm/traps.h>
34 #include <asm/unwind.h>
35 #include <asm/tls.h>
36 #include <asm/system_misc.h>
38 static const char *handler[]= {
39 "prefetch abort",
40 "data abort",
41 "address exception",
42 "interrupt",
43 "undefined instruction",
46 void *vectors_page;
48 #ifdef CONFIG_DEBUG_USER
49 unsigned int user_debug;
51 static int __init user_debug_setup(char *str)
53 get_option(&str, &user_debug);
54 return 1;
56 __setup("user_debug=", user_debug_setup);
57 #endif
59 static void dump_mem(const char *, const char *, unsigned long, unsigned long);
61 void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame)
63 #ifdef CONFIG_KALLSYMS
64 printk("[<%08lx>] (%pS) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from);
65 #else
66 printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from);
67 #endif
69 if (in_exception_text(where))
70 dump_mem("", "Exception stack", frame + 4, frame + 4 + sizeof(struct pt_regs));
73 #ifndef CONFIG_ARM_UNWIND
75 * Stack pointers should always be within the kernels view of
76 * physical memory. If it is not there, then we can't dump
77 * out any information relating to the stack.
79 static int verify_stack(unsigned long sp)
81 if (sp < PAGE_OFFSET ||
82 (sp > (unsigned long)high_memory && high_memory != NULL))
83 return -EFAULT;
85 return 0;
87 #endif
90 * Dump out the contents of some memory nicely...
92 static void dump_mem(const char *lvl, const char *str, unsigned long bottom,
93 unsigned long top)
95 unsigned long first;
96 mm_segment_t fs;
97 int i;
100 * We need to switch to kernel mode so that we can use __get_user
101 * to safely read from kernel space. Note that we now dump the
102 * code first, just in case the backtrace kills us.
104 fs = get_fs();
105 set_fs(KERNEL_DS);
107 printk("%s%s(0x%08lx to 0x%08lx)\n", lvl, str, bottom, top);
109 for (first = bottom & ~31; first < top; first += 32) {
110 unsigned long p;
111 char str[sizeof(" 12345678") * 8 + 1];
113 memset(str, ' ', sizeof(str));
114 str[sizeof(str) - 1] = '\0';
116 for (p = first, i = 0; i < 8 && p < top; i++, p += 4) {
117 if (p >= bottom && p < top) {
118 unsigned long val;
119 if (__get_user(val, (unsigned long *)p) == 0)
120 sprintf(str + i * 9, " %08lx", val);
121 else
122 sprintf(str + i * 9, " ????????");
125 printk("%s%04lx:%s\n", lvl, first & 0xffff, str);
128 set_fs(fs);
131 static void dump_instr(const char *lvl, struct pt_regs *regs)
133 unsigned long addr = instruction_pointer(regs);
134 const int thumb = thumb_mode(regs);
135 const int width = thumb ? 4 : 8;
136 mm_segment_t fs;
137 char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
138 int i;
141 * We need to switch to kernel mode so that we can use __get_user
142 * to safely read from kernel space. Note that we now dump the
143 * code first, just in case the backtrace kills us.
145 fs = get_fs();
146 set_fs(KERNEL_DS);
148 for (i = -4; i < 1 + !!thumb; i++) {
149 unsigned int val, bad;
151 if (thumb)
152 bad = __get_user(val, &((u16 *)addr)[i]);
153 else
154 bad = __get_user(val, &((u32 *)addr)[i]);
156 if (!bad)
157 p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ",
158 width, val);
159 else {
160 p += sprintf(p, "bad PC value");
161 break;
164 printk("%sCode: %s\n", lvl, str);
166 set_fs(fs);
169 #ifdef CONFIG_ARM_UNWIND
170 static inline void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
172 unwind_backtrace(regs, tsk);
174 #else
175 static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
177 unsigned int fp, mode;
178 int ok = 1;
180 printk("Backtrace: ");
182 if (!tsk)
183 tsk = current;
185 if (regs) {
186 fp = regs->ARM_fp;
187 mode = processor_mode(regs);
188 } else if (tsk != current) {
189 fp = thread_saved_fp(tsk);
190 mode = 0x10;
191 } else {
192 asm("mov %0, fp" : "=r" (fp) : : "cc");
193 mode = 0x10;
196 if (!fp) {
197 printk("no frame pointer");
198 ok = 0;
199 } else if (verify_stack(fp)) {
200 printk("invalid frame pointer 0x%08x", fp);
201 ok = 0;
202 } else if (fp < (unsigned long)end_of_stack(tsk))
203 printk("frame pointer underflow");
204 printk("\n");
206 if (ok)
207 c_backtrace(fp, mode);
209 #endif
211 void show_stack(struct task_struct *tsk, unsigned long *sp)
213 dump_backtrace(NULL, tsk);
214 barrier();
217 #ifdef CONFIG_PREEMPT
218 #define S_PREEMPT " PREEMPT"
219 #else
220 #define S_PREEMPT ""
221 #endif
222 #ifdef CONFIG_SMP
223 #define S_SMP " SMP"
224 #else
225 #define S_SMP ""
226 #endif
227 #ifdef CONFIG_THUMB2_KERNEL
228 #define S_ISA " THUMB2"
229 #else
230 #define S_ISA " ARM"
231 #endif
233 static int __die(const char *str, int err, struct pt_regs *regs)
235 struct task_struct *tsk = current;
236 static int die_counter;
237 int ret;
239 printk(KERN_EMERG "Internal error: %s: %x [#%d]" S_PREEMPT S_SMP
240 S_ISA "\n", str, err, ++die_counter);
242 /* trap and error numbers are mostly meaningless on ARM */
243 ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, SIGSEGV);
244 if (ret == NOTIFY_STOP)
245 return 1;
247 print_modules();
248 __show_regs(regs);
249 printk(KERN_EMERG "Process %.*s (pid: %d, stack limit = 0x%p)\n",
250 TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), end_of_stack(tsk));
252 if (!user_mode(regs) || in_interrupt()) {
253 dump_mem(KERN_EMERG, "Stack: ", regs->ARM_sp,
254 THREAD_SIZE + (unsigned long)task_stack_page(tsk));
255 dump_backtrace(regs, tsk);
256 dump_instr(KERN_EMERG, regs);
259 return 0;
262 static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
263 static int die_owner = -1;
264 static unsigned int die_nest_count;
266 static unsigned long oops_begin(void)
268 int cpu;
269 unsigned long flags;
271 oops_enter();
273 /* racy, but better than risking deadlock. */
274 raw_local_irq_save(flags);
275 cpu = smp_processor_id();
276 if (!arch_spin_trylock(&die_lock)) {
277 if (cpu == die_owner)
278 /* nested oops. should stop eventually */;
279 else
280 arch_spin_lock(&die_lock);
282 die_nest_count++;
283 die_owner = cpu;
284 console_verbose();
285 bust_spinlocks(1);
286 return flags;
289 static void oops_end(unsigned long flags, struct pt_regs *regs, int signr)
291 if (regs && kexec_should_crash(current))
292 crash_kexec(regs);
294 bust_spinlocks(0);
295 die_owner = -1;
296 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
297 die_nest_count--;
298 if (!die_nest_count)
299 /* Nest count reaches zero, release the lock. */
300 arch_spin_unlock(&die_lock);
301 raw_local_irq_restore(flags);
302 oops_exit();
304 if (in_interrupt())
305 panic("Fatal exception in interrupt");
306 if (panic_on_oops)
307 panic("Fatal exception");
308 if (signr)
309 do_exit(signr);
313 * This function is protected against re-entrancy.
315 void die(const char *str, struct pt_regs *regs, int err)
317 enum bug_trap_type bug_type = BUG_TRAP_TYPE_NONE;
318 unsigned long flags = oops_begin();
319 int sig = SIGSEGV;
321 if (!user_mode(regs))
322 bug_type = report_bug(regs->ARM_pc, regs);
323 if (bug_type != BUG_TRAP_TYPE_NONE)
324 str = "Oops - BUG";
326 if (__die(str, err, regs))
327 sig = 0;
329 oops_end(flags, regs, sig);
332 void arm_notify_die(const char *str, struct pt_regs *regs,
333 struct siginfo *info, unsigned long err, unsigned long trap)
335 if (user_mode(regs)) {
336 current->thread.error_code = err;
337 current->thread.trap_no = trap;
339 force_sig_info(info->si_signo, info, current);
340 } else {
341 die(str, regs, err);
345 #ifdef CONFIG_GENERIC_BUG
347 int is_valid_bugaddr(unsigned long pc)
349 #ifdef CONFIG_THUMB2_KERNEL
350 unsigned short bkpt;
351 #else
352 unsigned long bkpt;
353 #endif
355 if (probe_kernel_address((unsigned *)pc, bkpt))
356 return 0;
358 return bkpt == BUG_INSTR_VALUE;
361 #endif
363 static LIST_HEAD(undef_hook);
364 static DEFINE_RAW_SPINLOCK(undef_lock);
366 void register_undef_hook(struct undef_hook *hook)
368 unsigned long flags;
370 raw_spin_lock_irqsave(&undef_lock, flags);
371 list_add(&hook->node, &undef_hook);
372 raw_spin_unlock_irqrestore(&undef_lock, flags);
375 void unregister_undef_hook(struct undef_hook *hook)
377 unsigned long flags;
379 raw_spin_lock_irqsave(&undef_lock, flags);
380 list_del(&hook->node);
381 raw_spin_unlock_irqrestore(&undef_lock, flags);
384 static int call_undef_hook(struct pt_regs *regs, unsigned int instr)
386 struct undef_hook *hook;
387 unsigned long flags;
388 int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL;
390 raw_spin_lock_irqsave(&undef_lock, flags);
391 list_for_each_entry(hook, &undef_hook, node)
392 if ((instr & hook->instr_mask) == hook->instr_val &&
393 (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val)
394 fn = hook->fn;
395 raw_spin_unlock_irqrestore(&undef_lock, flags);
397 return fn ? fn(regs, instr) : 1;
400 asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
402 unsigned int instr;
403 siginfo_t info;
404 void __user *pc;
406 pc = (void __user *)instruction_pointer(regs);
408 if (processor_mode(regs) == SVC_MODE) {
409 #ifdef CONFIG_THUMB2_KERNEL
410 if (thumb_mode(regs)) {
411 instr = ((u16 *)pc)[0];
412 if (is_wide_instruction(instr)) {
413 instr <<= 16;
414 instr |= ((u16 *)pc)[1];
416 } else
417 #endif
418 instr = *(u32 *) pc;
419 } else if (thumb_mode(regs)) {
420 if (get_user(instr, (u16 __user *)pc))
421 goto die_sig;
422 if (is_wide_instruction(instr)) {
423 unsigned int instr2;
424 if (get_user(instr2, (u16 __user *)pc+1))
425 goto die_sig;
426 instr <<= 16;
427 instr |= instr2;
429 } else if (get_user(instr, (u32 __user *)pc)) {
430 goto die_sig;
433 if (call_undef_hook(regs, instr) == 0)
434 return;
436 die_sig:
437 #ifdef CONFIG_DEBUG_USER
438 if (user_debug & UDBG_UNDEFINED) {
439 printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n",
440 current->comm, task_pid_nr(current), pc);
441 dump_instr(KERN_INFO, regs);
443 #endif
445 info.si_signo = SIGILL;
446 info.si_errno = 0;
447 info.si_code = ILL_ILLOPC;
448 info.si_addr = pc;
450 arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6);
453 asmlinkage void do_unexp_fiq (struct pt_regs *regs)
455 printk("Hmm. Unexpected FIQ received, but trying to continue\n");
456 printk("You may have a hardware problem...\n");
460 * bad_mode handles the impossible case in the vectors. If you see one of
461 * these, then it's extremely serious, and could mean you have buggy hardware.
462 * It never returns, and never tries to sync. We hope that we can at least
463 * dump out some state information...
465 asmlinkage void bad_mode(struct pt_regs *regs, int reason)
467 console_verbose();
469 printk(KERN_CRIT "Bad mode in %s handler detected\n", handler[reason]);
471 die("Oops - bad mode", regs, 0);
472 local_irq_disable();
473 panic("bad mode");
476 static int bad_syscall(int n, struct pt_regs *regs)
478 struct thread_info *thread = current_thread_info();
479 siginfo_t info;
481 if ((current->personality & PER_MASK) != PER_LINUX &&
482 thread->exec_domain->handler) {
483 thread->exec_domain->handler(n, regs);
484 return regs->ARM_r0;
487 #ifdef CONFIG_DEBUG_USER
488 if (user_debug & UDBG_SYSCALL) {
489 printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n",
490 task_pid_nr(current), current->comm, n);
491 dump_instr(KERN_ERR, regs);
493 #endif
495 info.si_signo = SIGILL;
496 info.si_errno = 0;
497 info.si_code = ILL_ILLTRP;
498 info.si_addr = (void __user *)instruction_pointer(regs) -
499 (thumb_mode(regs) ? 2 : 4);
501 arm_notify_die("Oops - bad syscall", regs, &info, n, 0);
503 return regs->ARM_r0;
506 static long do_cache_op_restart(struct restart_block *);
508 static inline int
509 __do_cache_op(unsigned long start, unsigned long end)
511 int ret;
513 do {
514 unsigned long chunk = min(PAGE_SIZE, end - start);
516 if (signal_pending(current)) {
517 struct thread_info *ti = current_thread_info();
519 ti->restart_block = (struct restart_block) {
520 .fn = do_cache_op_restart,
523 ti->arm_restart_block = (struct arm_restart_block) {
525 .cache = {
526 .start = start,
527 .end = end,
532 return -ERESTART_RESTARTBLOCK;
535 ret = flush_cache_user_range(start, start + chunk);
536 if (ret)
537 return ret;
539 cond_resched();
540 start += chunk;
541 } while (start < end);
543 return 0;
546 static long do_cache_op_restart(struct restart_block *unused)
548 struct arm_restart_block *restart_block;
550 restart_block = &current_thread_info()->arm_restart_block;
551 return __do_cache_op(restart_block->cache.start,
552 restart_block->cache.end);
555 static inline int
556 do_cache_op(unsigned long start, unsigned long end, int flags)
558 if (end < start || flags)
559 return -EINVAL;
561 if (!access_ok(VERIFY_READ, start, end - start))
562 return -EFAULT;
564 return __do_cache_op(start, end);
568 * Handle all unrecognised system calls.
569 * 0x9f0000 - 0x9fffff are some more esoteric system calls
571 #define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE)
572 asmlinkage int arm_syscall(int no, struct pt_regs *regs)
574 struct thread_info *thread = current_thread_info();
575 siginfo_t info;
577 if ((no >> 16) != (__ARM_NR_BASE>> 16))
578 return bad_syscall(no, regs);
580 switch (no & 0xffff) {
581 case 0: /* branch through 0 */
582 info.si_signo = SIGSEGV;
583 info.si_errno = 0;
584 info.si_code = SEGV_MAPERR;
585 info.si_addr = NULL;
587 arm_notify_die("branch through zero", regs, &info, 0, 0);
588 return 0;
590 case NR(breakpoint): /* SWI BREAK_POINT */
591 regs->ARM_pc -= thumb_mode(regs) ? 2 : 4;
592 ptrace_break(current, regs);
593 return regs->ARM_r0;
596 * Flush a region from virtual address 'r0' to virtual address 'r1'
597 * _exclusive_. There is no alignment requirement on either address;
598 * user space does not need to know the hardware cache layout.
600 * r2 contains flags. It should ALWAYS be passed as ZERO until it
601 * is defined to be something else. For now we ignore it, but may
602 * the fires of hell burn in your belly if you break this rule. ;)
604 * (at a later date, we may want to allow this call to not flush
605 * various aspects of the cache. Passing '0' will guarantee that
606 * everything necessary gets flushed to maintain consistency in
607 * the specified region).
609 case NR(cacheflush):
610 return do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2);
612 case NR(usr26):
613 if (!(elf_hwcap & HWCAP_26BIT))
614 break;
615 regs->ARM_cpsr &= ~MODE32_BIT;
616 return regs->ARM_r0;
618 case NR(usr32):
619 if (!(elf_hwcap & HWCAP_26BIT))
620 break;
621 regs->ARM_cpsr |= MODE32_BIT;
622 return regs->ARM_r0;
624 case NR(set_tls):
625 thread->tp_value[0] = regs->ARM_r0;
626 if (tls_emu)
627 return 0;
628 if (has_tls_reg) {
629 asm ("mcr p15, 0, %0, c13, c0, 3"
630 : : "r" (regs->ARM_r0));
631 } else {
633 * User space must never try to access this directly.
634 * Expect your app to break eventually if you do so.
635 * The user helper at 0xffff0fe0 must be used instead.
636 * (see entry-armv.S for details)
638 *((unsigned int *)0xffff0ff0) = regs->ARM_r0;
640 return 0;
642 #ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG
644 * Atomically store r1 in *r2 if *r2 is equal to r0 for user space.
645 * Return zero in r0 if *MEM was changed or non-zero if no exchange
646 * happened. Also set the user C flag accordingly.
647 * If access permissions have to be fixed up then non-zero is
648 * returned and the operation has to be re-attempted.
650 * *NOTE*: This is a ghost syscall private to the kernel. Only the
651 * __kuser_cmpxchg code in entry-armv.S should be aware of its
652 * existence. Don't ever use this from user code.
654 case NR(cmpxchg):
655 for (;;) {
656 extern void do_DataAbort(unsigned long addr, unsigned int fsr,
657 struct pt_regs *regs);
658 unsigned long val;
659 unsigned long addr = regs->ARM_r2;
660 struct mm_struct *mm = current->mm;
661 pgd_t *pgd; pmd_t *pmd; pte_t *pte;
662 spinlock_t *ptl;
664 regs->ARM_cpsr &= ~PSR_C_BIT;
665 down_read(&mm->mmap_sem);
666 pgd = pgd_offset(mm, addr);
667 if (!pgd_present(*pgd))
668 goto bad_access;
669 pmd = pmd_offset(pgd, addr);
670 if (!pmd_present(*pmd))
671 goto bad_access;
672 pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
673 if (!pte_present(*pte) || !pte_write(*pte) || !pte_dirty(*pte)) {
674 pte_unmap_unlock(pte, ptl);
675 goto bad_access;
677 val = *(unsigned long *)addr;
678 val -= regs->ARM_r0;
679 if (val == 0) {
680 *(unsigned long *)addr = regs->ARM_r1;
681 regs->ARM_cpsr |= PSR_C_BIT;
683 pte_unmap_unlock(pte, ptl);
684 up_read(&mm->mmap_sem);
685 return val;
687 bad_access:
688 up_read(&mm->mmap_sem);
689 /* simulate a write access fault */
690 do_DataAbort(addr, 15 + (1 << 11), regs);
692 #endif
694 default:
695 /* Calls 9f00xx..9f07ff are defined to return -ENOSYS
696 if not implemented, rather than raising SIGILL. This
697 way the calling program can gracefully determine whether
698 a feature is supported. */
699 if ((no & 0xffff) <= 0x7ff)
700 return -ENOSYS;
701 break;
703 #ifdef CONFIG_DEBUG_USER
705 * experience shows that these seem to indicate that
706 * something catastrophic has happened
708 if (user_debug & UDBG_SYSCALL) {
709 printk("[%d] %s: arm syscall %d\n",
710 task_pid_nr(current), current->comm, no);
711 dump_instr("", regs);
712 if (user_mode(regs)) {
713 __show_regs(regs);
714 c_backtrace(regs->ARM_fp, processor_mode(regs));
717 #endif
718 info.si_signo = SIGILL;
719 info.si_errno = 0;
720 info.si_code = ILL_ILLTRP;
721 info.si_addr = (void __user *)instruction_pointer(regs) -
722 (thumb_mode(regs) ? 2 : 4);
724 arm_notify_die("Oops - bad syscall(2)", regs, &info, no, 0);
725 return 0;
728 #ifdef CONFIG_TLS_REG_EMUL
731 * We might be running on an ARMv6+ processor which should have the TLS
732 * register but for some reason we can't use it, or maybe an SMP system
733 * using a pre-ARMv6 processor (there are apparently a few prototypes like
734 * that in existence) and therefore access to that register must be
735 * emulated.
738 static int get_tp_trap(struct pt_regs *regs, unsigned int instr)
740 int reg = (instr >> 12) & 15;
741 if (reg == 15)
742 return 1;
743 regs->uregs[reg] = current_thread_info()->tp_value[0];
744 regs->ARM_pc += 4;
745 return 0;
748 static struct undef_hook arm_mrc_hook = {
749 .instr_mask = 0x0fff0fff,
750 .instr_val = 0x0e1d0f70,
751 .cpsr_mask = PSR_T_BIT,
752 .cpsr_val = 0,
753 .fn = get_tp_trap,
756 static int __init arm_mrc_hook_init(void)
758 register_undef_hook(&arm_mrc_hook);
759 return 0;
762 late_initcall(arm_mrc_hook_init);
764 #endif
766 void __bad_xchg(volatile void *ptr, int size)
768 printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n",
769 __builtin_return_address(0), ptr, size);
770 BUG();
772 EXPORT_SYMBOL(__bad_xchg);
775 * A data abort trap was taken, but we did not handle the instruction.
776 * Try to abort the user program, or panic if it was the kernel.
778 asmlinkage void
779 baddataabort(int code, unsigned long instr, struct pt_regs *regs)
781 unsigned long addr = instruction_pointer(regs);
782 siginfo_t info;
784 #ifdef CONFIG_DEBUG_USER
785 if (user_debug & UDBG_BADABORT) {
786 printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n",
787 task_pid_nr(current), current->comm, code, instr);
788 dump_instr(KERN_ERR, regs);
789 show_pte(current->mm, addr);
791 #endif
793 info.si_signo = SIGILL;
794 info.si_errno = 0;
795 info.si_code = ILL_ILLOPC;
796 info.si_addr = (void __user *)addr;
798 arm_notify_die("unknown data abort code", regs, &info, instr, 0);
801 void __readwrite_bug(const char *fn)
803 printk("%s called, but not implemented\n", fn);
804 BUG();
806 EXPORT_SYMBOL(__readwrite_bug);
808 void __pte_error(const char *file, int line, pte_t pte)
810 printk("%s:%d: bad pte %08llx.\n", file, line, (long long)pte_val(pte));
813 void __pmd_error(const char *file, int line, pmd_t pmd)
815 printk("%s:%d: bad pmd %08llx.\n", file, line, (long long)pmd_val(pmd));
818 void __pgd_error(const char *file, int line, pgd_t pgd)
820 printk("%s:%d: bad pgd %08llx.\n", file, line, (long long)pgd_val(pgd));
823 asmlinkage void __div0(void)
825 printk("Division by zero in kernel.\n");
826 dump_stack();
828 EXPORT_SYMBOL(__div0);
830 void abort(void)
832 BUG();
834 /* if that doesn't kill us, halt */
835 panic("Oops failed to kill thread");
837 EXPORT_SYMBOL(abort);
839 void __init trap_init(void)
841 return;
844 #ifdef CONFIG_KUSER_HELPERS
845 static void __init kuser_init(void *vectors)
847 extern char __kuser_helper_start[], __kuser_helper_end[];
848 int kuser_sz = __kuser_helper_end - __kuser_helper_start;
850 memcpy(vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz);
853 * vectors + 0xfe0 = __kuser_get_tls
854 * vectors + 0xfe8 = hardware TLS instruction at 0xffff0fe8
856 if (tls_emu || has_tls_reg)
857 memcpy(vectors + 0xfe0, vectors + 0xfe8, 4);
859 #else
860 static void __init kuser_init(void *vectors)
863 #endif
865 void __init early_trap_init(void *vectors_base)
867 #ifndef CONFIG_CPU_V7M
868 unsigned long vectors = (unsigned long)vectors_base;
869 extern char __stubs_start[], __stubs_end[];
870 extern char __vectors_start[], __vectors_end[];
871 unsigned i;
873 vectors_page = vectors_base;
876 * Poison the vectors page with an undefined instruction. This
877 * instruction is chosen to be undefined for both ARM and Thumb
878 * ISAs. The Thumb version is an undefined instruction with a
879 * branch back to the undefined instruction.
881 for (i = 0; i < PAGE_SIZE / sizeof(u32); i++)
882 ((u32 *)vectors_base)[i] = 0xe7fddef1;
885 * Copy the vectors, stubs and kuser helpers (in entry-armv.S)
886 * into the vector page, mapped at 0xffff0000, and ensure these
887 * are visible to the instruction stream.
889 memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start);
890 memcpy((void *)vectors + 0x1000, __stubs_start, __stubs_end - __stubs_start);
892 kuser_init(vectors_base);
894 flush_icache_range(vectors, vectors + PAGE_SIZE * 2);
895 modify_domain(DOMAIN_USER, DOMAIN_CLIENT);
896 #else /* ifndef CONFIG_CPU_V7M */
898 * on V7-M there is no need to copy the vector table to a dedicated
899 * memory area. The address is configurable and so a table in the kernel
900 * image can be used.
902 #endif