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>
28 #include <linux/irq.h>
30 #include <linux/atomic.h>
31 #include <asm/cacheflush.h>
32 #include <asm/exception.h>
33 #include <asm/unistd.h>
34 #include <asm/traps.h>
35 #include <asm/ptrace.h>
36 #include <asm/unwind.h>
38 #include <asm/system_misc.h>
39 #include <asm/opcodes.h>
42 static const char *handler
[]= {
47 "undefined instruction",
52 #ifdef CONFIG_DEBUG_USER
53 unsigned int user_debug
;
55 static int __init
user_debug_setup(char *str
)
57 get_option(&str
, &user_debug
);
60 __setup("user_debug=", user_debug_setup
);
63 static void dump_mem(const char *, const char *, unsigned long, unsigned long);
65 void dump_backtrace_entry(unsigned long where
, unsigned long from
, unsigned long frame
)
67 #ifdef CONFIG_KALLSYMS
68 printk("[<%08lx>] (%ps) from [<%08lx>] (%pS)\n", where
, (void *)where
, from
, (void *)from
);
70 printk("Function entered at [<%08lx>] from [<%08lx>]\n", where
, from
);
73 if (in_exception_text(where
))
74 dump_mem("", "Exception stack", frame
+ 4, frame
+ 4 + sizeof(struct pt_regs
));
77 #ifndef CONFIG_ARM_UNWIND
79 * Stack pointers should always be within the kernels view of
80 * physical memory. If it is not there, then we can't dump
81 * out any information relating to the stack.
83 static int verify_stack(unsigned long sp
)
85 if (sp
< PAGE_OFFSET
||
86 (sp
> (unsigned long)high_memory
&& high_memory
!= NULL
))
94 * Dump out the contents of some memory nicely...
96 static void dump_mem(const char *lvl
, const char *str
, unsigned long bottom
,
104 * We need to switch to kernel mode so that we can use __get_user
105 * to safely read from kernel space. Note that we now dump the
106 * code first, just in case the backtrace kills us.
111 printk("%s%s(0x%08lx to 0x%08lx)\n", lvl
, str
, bottom
, top
);
113 for (first
= bottom
& ~31; first
< top
; first
+= 32) {
115 char str
[sizeof(" 12345678") * 8 + 1];
117 memset(str
, ' ', sizeof(str
));
118 str
[sizeof(str
) - 1] = '\0';
120 for (p
= first
, i
= 0; i
< 8 && p
< top
; i
++, p
+= 4) {
121 if (p
>= bottom
&& p
< top
) {
123 if (__get_user(val
, (unsigned long *)p
) == 0)
124 sprintf(str
+ i
* 9, " %08lx", val
);
126 sprintf(str
+ i
* 9, " ????????");
129 printk("%s%04lx:%s\n", lvl
, first
& 0xffff, str
);
135 static void dump_instr(const char *lvl
, struct pt_regs
*regs
)
137 unsigned long addr
= instruction_pointer(regs
);
138 const int thumb
= thumb_mode(regs
);
139 const int width
= thumb
? 4 : 8;
141 char str
[sizeof("00000000 ") * 5 + 2 + 1], *p
= str
;
145 * We need to switch to kernel mode so that we can use __get_user
146 * to safely read from kernel space. Note that we now dump the
147 * code first, just in case the backtrace kills us.
152 for (i
= -4; i
< 1 + !!thumb
; i
++) {
153 unsigned int val
, bad
;
156 bad
= __get_user(val
, &((u16
*)addr
)[i
]);
158 bad
= __get_user(val
, &((u32
*)addr
)[i
]);
161 p
+= sprintf(p
, i
== 0 ? "(%0*x) " : "%0*x ",
164 p
+= sprintf(p
, "bad PC value");
168 printk("%sCode: %s\n", lvl
, str
);
173 #ifdef CONFIG_ARM_UNWIND
174 static inline void dump_backtrace(struct pt_regs
*regs
, struct task_struct
*tsk
)
176 unwind_backtrace(regs
, tsk
);
179 static void dump_backtrace(struct pt_regs
*regs
, struct task_struct
*tsk
)
181 unsigned int fp
, mode
;
184 printk("Backtrace: ");
190 fp
= frame_pointer(regs
);
191 mode
= processor_mode(regs
);
192 } else if (tsk
!= current
) {
193 fp
= thread_saved_fp(tsk
);
196 asm("mov %0, fp" : "=r" (fp
) : : "cc");
201 printk("no frame pointer");
203 } else if (verify_stack(fp
)) {
204 printk("invalid frame pointer 0x%08x", fp
);
206 } else if (fp
< (unsigned long)end_of_stack(tsk
))
207 printk("frame pointer underflow");
211 c_backtrace(fp
, mode
);
215 void show_stack(struct task_struct
*tsk
, unsigned long *sp
)
217 dump_backtrace(NULL
, tsk
);
221 #ifdef CONFIG_PREEMPT
222 #define S_PREEMPT " PREEMPT"
231 #ifdef CONFIG_THUMB2_KERNEL
232 #define S_ISA " THUMB2"
237 static int __die(const char *str
, int err
, struct pt_regs
*regs
)
239 struct task_struct
*tsk
= current
;
240 static int die_counter
;
243 printk(KERN_EMERG
"Internal error: %s: %x [#%d]" S_PREEMPT S_SMP
244 S_ISA
"\n", str
, err
, ++die_counter
);
246 /* trap and error numbers are mostly meaningless on ARM */
247 ret
= notify_die(DIE_OOPS
, str
, regs
, err
, tsk
->thread
.trap_no
, SIGSEGV
);
248 if (ret
== NOTIFY_STOP
)
253 printk(KERN_EMERG
"Process %.*s (pid: %d, stack limit = 0x%p)\n",
254 TASK_COMM_LEN
, tsk
->comm
, task_pid_nr(tsk
), end_of_stack(tsk
));
256 if (!user_mode(regs
) || in_interrupt()) {
257 dump_mem(KERN_EMERG
, "Stack: ", regs
->ARM_sp
,
258 THREAD_SIZE
+ (unsigned long)task_stack_page(tsk
));
259 dump_backtrace(regs
, tsk
);
260 dump_instr(KERN_EMERG
, regs
);
266 static arch_spinlock_t die_lock
= __ARCH_SPIN_LOCK_UNLOCKED
;
267 static int die_owner
= -1;
268 static unsigned int die_nest_count
;
270 static unsigned long oops_begin(void)
277 /* racy, but better than risking deadlock. */
278 raw_local_irq_save(flags
);
279 cpu
= smp_processor_id();
280 if (!arch_spin_trylock(&die_lock
)) {
281 if (cpu
== die_owner
)
282 /* nested oops. should stop eventually */;
284 arch_spin_lock(&die_lock
);
293 static void oops_end(unsigned long flags
, struct pt_regs
*regs
, int signr
)
295 if (regs
&& kexec_should_crash(current
))
300 add_taint(TAINT_DIE
, LOCKDEP_NOW_UNRELIABLE
);
303 /* Nest count reaches zero, release the lock. */
304 arch_spin_unlock(&die_lock
);
305 raw_local_irq_restore(flags
);
309 panic("Fatal exception in interrupt");
311 panic("Fatal exception");
317 * This function is protected against re-entrancy.
319 void die(const char *str
, struct pt_regs
*regs
, int err
)
321 enum bug_trap_type bug_type
= BUG_TRAP_TYPE_NONE
;
322 unsigned long flags
= oops_begin();
325 if (!user_mode(regs
))
326 bug_type
= report_bug(regs
->ARM_pc
, regs
);
327 if (bug_type
!= BUG_TRAP_TYPE_NONE
)
330 if (__die(str
, err
, regs
))
333 oops_end(flags
, regs
, sig
);
336 void arm_notify_die(const char *str
, struct pt_regs
*regs
,
337 struct siginfo
*info
, unsigned long err
, unsigned long trap
)
339 if (user_mode(regs
)) {
340 current
->thread
.error_code
= err
;
341 current
->thread
.trap_no
= trap
;
343 force_sig_info(info
->si_signo
, info
, current
);
349 #ifdef CONFIG_GENERIC_BUG
351 int is_valid_bugaddr(unsigned long pc
)
353 #ifdef CONFIG_THUMB2_KERNEL
355 u16 insn
= __opcode_to_mem_thumb16(BUG_INSTR_VALUE
);
358 u32 insn
= __opcode_to_mem_arm(BUG_INSTR_VALUE
);
361 if (probe_kernel_address((unsigned *)pc
, bkpt
))
369 static LIST_HEAD(undef_hook
);
370 static DEFINE_RAW_SPINLOCK(undef_lock
);
372 void register_undef_hook(struct undef_hook
*hook
)
376 raw_spin_lock_irqsave(&undef_lock
, flags
);
377 list_add(&hook
->node
, &undef_hook
);
378 raw_spin_unlock_irqrestore(&undef_lock
, flags
);
381 void unregister_undef_hook(struct undef_hook
*hook
)
385 raw_spin_lock_irqsave(&undef_lock
, flags
);
386 list_del(&hook
->node
);
387 raw_spin_unlock_irqrestore(&undef_lock
, flags
);
390 static int call_undef_hook(struct pt_regs
*regs
, unsigned int instr
)
392 struct undef_hook
*hook
;
394 int (*fn
)(struct pt_regs
*regs
, unsigned int instr
) = NULL
;
396 raw_spin_lock_irqsave(&undef_lock
, flags
);
397 list_for_each_entry(hook
, &undef_hook
, node
)
398 if ((instr
& hook
->instr_mask
) == hook
->instr_val
&&
399 (regs
->ARM_cpsr
& hook
->cpsr_mask
) == hook
->cpsr_val
)
401 raw_spin_unlock_irqrestore(&undef_lock
, flags
);
403 return fn
? fn(regs
, instr
) : 1;
406 asmlinkage
void __exception
do_undefinstr(struct pt_regs
*regs
)
412 pc
= (void __user
*)instruction_pointer(regs
);
414 if (processor_mode(regs
) == SVC_MODE
) {
415 #ifdef CONFIG_THUMB2_KERNEL
416 if (thumb_mode(regs
)) {
417 instr
= __mem_to_opcode_thumb16(((u16
*)pc
)[0]);
418 if (is_wide_instruction(instr
)) {
420 inst2
= __mem_to_opcode_thumb16(((u16
*)pc
)[1]);
421 instr
= __opcode_thumb32_compose(instr
, inst2
);
425 instr
= __mem_to_opcode_arm(*(u32
*) pc
);
426 } else if (thumb_mode(regs
)) {
427 if (get_user(instr
, (u16 __user
*)pc
))
429 instr
= __mem_to_opcode_thumb16(instr
);
430 if (is_wide_instruction(instr
)) {
432 if (get_user(instr2
, (u16 __user
*)pc
+1))
434 instr2
= __mem_to_opcode_thumb16(instr2
);
435 instr
= __opcode_thumb32_compose(instr
, instr2
);
438 if (get_user(instr
, (u32 __user
*)pc
))
440 instr
= __mem_to_opcode_arm(instr
);
443 if (call_undef_hook(regs
, instr
) == 0)
447 #ifdef CONFIG_DEBUG_USER
448 if (user_debug
& UDBG_UNDEFINED
) {
449 printk(KERN_INFO
"%s (%d): undefined instruction: pc=%p\n",
450 current
->comm
, task_pid_nr(current
), pc
);
452 dump_instr(KERN_INFO
, regs
);
456 info
.si_signo
= SIGILL
;
458 info
.si_code
= ILL_ILLOPC
;
461 arm_notify_die("Oops - undefined instruction", regs
, &info
, 0, 6);
465 * Handle FIQ similarly to NMI on x86 systems.
467 * The runtime environment for NMIs is extremely restrictive
468 * (NMIs can pre-empt critical sections meaning almost all locking is
469 * forbidden) meaning this default FIQ handling must only be used in
470 * circumstances where non-maskability improves robustness, such as
471 * watchdog or debug logic.
473 * This handler is not appropriate for general purpose use in drivers
474 * platform code and can be overrideen using set_fiq_handler.
476 asmlinkage
void __exception_irq_entry
handle_fiq_as_nmi(struct pt_regs
*regs
)
478 struct pt_regs
*old_regs
= set_irq_regs(regs
);
482 /* nop. FIQ handlers for special arch/arm features can be added here. */
486 set_irq_regs(old_regs
);
490 * bad_mode handles the impossible case in the vectors. If you see one of
491 * these, then it's extremely serious, and could mean you have buggy hardware.
492 * It never returns, and never tries to sync. We hope that we can at least
493 * dump out some state information...
495 asmlinkage
void bad_mode(struct pt_regs
*regs
, int reason
)
499 printk(KERN_CRIT
"Bad mode in %s handler detected\n", handler
[reason
]);
501 die("Oops - bad mode", regs
, 0);
506 static int bad_syscall(int n
, struct pt_regs
*regs
)
508 struct thread_info
*thread
= current_thread_info();
511 if ((current
->personality
& PER_MASK
) != PER_LINUX
&&
512 thread
->exec_domain
->handler
) {
513 thread
->exec_domain
->handler(n
, regs
);
517 #ifdef CONFIG_DEBUG_USER
518 if (user_debug
& UDBG_SYSCALL
) {
519 printk(KERN_ERR
"[%d] %s: obsolete system call %08x.\n",
520 task_pid_nr(current
), current
->comm
, n
);
521 dump_instr(KERN_ERR
, regs
);
525 info
.si_signo
= SIGILL
;
527 info
.si_code
= ILL_ILLTRP
;
528 info
.si_addr
= (void __user
*)instruction_pointer(regs
) -
529 (thumb_mode(regs
) ? 2 : 4);
531 arm_notify_die("Oops - bad syscall", regs
, &info
, n
, 0);
536 static long do_cache_op_restart(struct restart_block
*);
539 __do_cache_op(unsigned long start
, unsigned long end
)
544 unsigned long chunk
= min(PAGE_SIZE
, end
- start
);
546 if (signal_pending(current
)) {
547 struct thread_info
*ti
= current_thread_info();
549 ti
->restart_block
= (struct restart_block
) {
550 .fn
= do_cache_op_restart
,
553 ti
->arm_restart_block
= (struct arm_restart_block
) {
562 return -ERESTART_RESTARTBLOCK
;
565 ret
= flush_cache_user_range(start
, start
+ chunk
);
571 } while (start
< end
);
576 static long do_cache_op_restart(struct restart_block
*unused
)
578 struct arm_restart_block
*restart_block
;
580 restart_block
= ¤t_thread_info()->arm_restart_block
;
581 return __do_cache_op(restart_block
->cache
.start
,
582 restart_block
->cache
.end
);
586 do_cache_op(unsigned long start
, unsigned long end
, int flags
)
588 if (end
< start
|| flags
)
591 if (!access_ok(VERIFY_READ
, start
, end
- start
))
594 return __do_cache_op(start
, end
);
598 * Handle all unrecognised system calls.
599 * 0x9f0000 - 0x9fffff are some more esoteric system calls
601 #define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE)
602 asmlinkage
int arm_syscall(int no
, struct pt_regs
*regs
)
606 if ((no
>> 16) != (__ARM_NR_BASE
>> 16))
607 return bad_syscall(no
, regs
);
609 switch (no
& 0xffff) {
610 case 0: /* branch through 0 */
611 info
.si_signo
= SIGSEGV
;
613 info
.si_code
= SEGV_MAPERR
;
616 arm_notify_die("branch through zero", regs
, &info
, 0, 0);
619 case NR(breakpoint
): /* SWI BREAK_POINT */
620 regs
->ARM_pc
-= thumb_mode(regs
) ? 2 : 4;
621 ptrace_break(current
, regs
);
625 * Flush a region from virtual address 'r0' to virtual address 'r1'
626 * _exclusive_. There is no alignment requirement on either address;
627 * user space does not need to know the hardware cache layout.
629 * r2 contains flags. It should ALWAYS be passed as ZERO until it
630 * is defined to be something else. For now we ignore it, but may
631 * the fires of hell burn in your belly if you break this rule. ;)
633 * (at a later date, we may want to allow this call to not flush
634 * various aspects of the cache. Passing '0' will guarantee that
635 * everything necessary gets flushed to maintain consistency in
636 * the specified region).
639 return do_cache_op(regs
->ARM_r0
, regs
->ARM_r1
, regs
->ARM_r2
);
642 if (!(elf_hwcap
& HWCAP_26BIT
))
644 regs
->ARM_cpsr
&= ~MODE32_BIT
;
648 if (!(elf_hwcap
& HWCAP_26BIT
))
650 regs
->ARM_cpsr
|= MODE32_BIT
;
654 set_tls(regs
->ARM_r0
);
657 #ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG
659 * Atomically store r1 in *r2 if *r2 is equal to r0 for user space.
660 * Return zero in r0 if *MEM was changed or non-zero if no exchange
661 * happened. Also set the user C flag accordingly.
662 * If access permissions have to be fixed up then non-zero is
663 * returned and the operation has to be re-attempted.
665 * *NOTE*: This is a ghost syscall private to the kernel. Only the
666 * __kuser_cmpxchg code in entry-armv.S should be aware of its
667 * existence. Don't ever use this from user code.
671 extern void do_DataAbort(unsigned long addr
, unsigned int fsr
,
672 struct pt_regs
*regs
);
674 unsigned long addr
= regs
->ARM_r2
;
675 struct mm_struct
*mm
= current
->mm
;
676 pgd_t
*pgd
; pmd_t
*pmd
; pte_t
*pte
;
679 regs
->ARM_cpsr
&= ~PSR_C_BIT
;
680 down_read(&mm
->mmap_sem
);
681 pgd
= pgd_offset(mm
, addr
);
682 if (!pgd_present(*pgd
))
684 pmd
= pmd_offset(pgd
, addr
);
685 if (!pmd_present(*pmd
))
687 pte
= pte_offset_map_lock(mm
, pmd
, addr
, &ptl
);
688 if (!pte_present(*pte
) || !pte_write(*pte
) || !pte_dirty(*pte
)) {
689 pte_unmap_unlock(pte
, ptl
);
692 val
= *(unsigned long *)addr
;
695 *(unsigned long *)addr
= regs
->ARM_r1
;
696 regs
->ARM_cpsr
|= PSR_C_BIT
;
698 pte_unmap_unlock(pte
, ptl
);
699 up_read(&mm
->mmap_sem
);
703 up_read(&mm
->mmap_sem
);
704 /* simulate a write access fault */
705 do_DataAbort(addr
, 15 + (1 << 11), regs
);
710 /* Calls 9f00xx..9f07ff are defined to return -ENOSYS
711 if not implemented, rather than raising SIGILL. This
712 way the calling program can gracefully determine whether
713 a feature is supported. */
714 if ((no
& 0xffff) <= 0x7ff)
718 #ifdef CONFIG_DEBUG_USER
720 * experience shows that these seem to indicate that
721 * something catastrophic has happened
723 if (user_debug
& UDBG_SYSCALL
) {
724 printk("[%d] %s: arm syscall %d\n",
725 task_pid_nr(current
), current
->comm
, no
);
726 dump_instr("", regs
);
727 if (user_mode(regs
)) {
729 c_backtrace(frame_pointer(regs
), processor_mode(regs
));
733 info
.si_signo
= SIGILL
;
735 info
.si_code
= ILL_ILLTRP
;
736 info
.si_addr
= (void __user
*)instruction_pointer(regs
) -
737 (thumb_mode(regs
) ? 2 : 4);
739 arm_notify_die("Oops - bad syscall(2)", regs
, &info
, no
, 0);
743 #ifdef CONFIG_TLS_REG_EMUL
746 * We might be running on an ARMv6+ processor which should have the TLS
747 * register but for some reason we can't use it, or maybe an SMP system
748 * using a pre-ARMv6 processor (there are apparently a few prototypes like
749 * that in existence) and therefore access to that register must be
753 static int get_tp_trap(struct pt_regs
*regs
, unsigned int instr
)
755 int reg
= (instr
>> 12) & 15;
758 regs
->uregs
[reg
] = current_thread_info()->tp_value
[0];
763 static struct undef_hook arm_mrc_hook
= {
764 .instr_mask
= 0x0fff0fff,
765 .instr_val
= 0x0e1d0f70,
766 .cpsr_mask
= PSR_T_BIT
,
771 static int __init
arm_mrc_hook_init(void)
773 register_undef_hook(&arm_mrc_hook
);
777 late_initcall(arm_mrc_hook_init
);
781 void __bad_xchg(volatile void *ptr
, int size
)
783 printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n",
784 __builtin_return_address(0), ptr
, size
);
787 EXPORT_SYMBOL(__bad_xchg
);
790 * A data abort trap was taken, but we did not handle the instruction.
791 * Try to abort the user program, or panic if it was the kernel.
794 baddataabort(int code
, unsigned long instr
, struct pt_regs
*regs
)
796 unsigned long addr
= instruction_pointer(regs
);
799 #ifdef CONFIG_DEBUG_USER
800 if (user_debug
& UDBG_BADABORT
) {
801 printk(KERN_ERR
"[%d] %s: bad data abort: code %d instr 0x%08lx\n",
802 task_pid_nr(current
), current
->comm
, code
, instr
);
803 dump_instr(KERN_ERR
, regs
);
804 show_pte(current
->mm
, addr
);
808 info
.si_signo
= SIGILL
;
810 info
.si_code
= ILL_ILLOPC
;
811 info
.si_addr
= (void __user
*)addr
;
813 arm_notify_die("unknown data abort code", regs
, &info
, instr
, 0);
816 void __readwrite_bug(const char *fn
)
818 printk("%s called, but not implemented\n", fn
);
821 EXPORT_SYMBOL(__readwrite_bug
);
823 void __pte_error(const char *file
, int line
, pte_t pte
)
825 printk("%s:%d: bad pte %08llx.\n", file
, line
, (long long)pte_val(pte
));
828 void __pmd_error(const char *file
, int line
, pmd_t pmd
)
830 printk("%s:%d: bad pmd %08llx.\n", file
, line
, (long long)pmd_val(pmd
));
833 void __pgd_error(const char *file
, int line
, pgd_t pgd
)
835 printk("%s:%d: bad pgd %08llx.\n", file
, line
, (long long)pgd_val(pgd
));
838 asmlinkage
void __div0(void)
840 printk("Division by zero in kernel.\n");
843 EXPORT_SYMBOL(__div0
);
849 /* if that doesn't kill us, halt */
850 panic("Oops failed to kill thread");
852 EXPORT_SYMBOL(abort
);
854 void __init
trap_init(void)
859 #ifdef CONFIG_KUSER_HELPERS
860 static void __init
kuser_init(void *vectors
)
862 extern char __kuser_helper_start
[], __kuser_helper_end
[];
863 int kuser_sz
= __kuser_helper_end
- __kuser_helper_start
;
865 memcpy(vectors
+ 0x1000 - kuser_sz
, __kuser_helper_start
, kuser_sz
);
868 * vectors + 0xfe0 = __kuser_get_tls
869 * vectors + 0xfe8 = hardware TLS instruction at 0xffff0fe8
871 if (tls_emu
|| has_tls_reg
)
872 memcpy(vectors
+ 0xfe0, vectors
+ 0xfe8, 4);
875 static inline void __init
kuser_init(void *vectors
)
880 void __init
early_trap_init(void *vectors_base
)
882 #ifndef CONFIG_CPU_V7M
883 unsigned long vectors
= (unsigned long)vectors_base
;
884 extern char __stubs_start
[], __stubs_end
[];
885 extern char __vectors_start
[], __vectors_end
[];
888 vectors_page
= vectors_base
;
891 * Poison the vectors page with an undefined instruction. This
892 * instruction is chosen to be undefined for both ARM and Thumb
893 * ISAs. The Thumb version is an undefined instruction with a
894 * branch back to the undefined instruction.
896 for (i
= 0; i
< PAGE_SIZE
/ sizeof(u32
); i
++)
897 ((u32
*)vectors_base
)[i
] = 0xe7fddef1;
900 * Copy the vectors, stubs and kuser helpers (in entry-armv.S)
901 * into the vector page, mapped at 0xffff0000, and ensure these
902 * are visible to the instruction stream.
904 memcpy((void *)vectors
, __vectors_start
, __vectors_end
- __vectors_start
);
905 memcpy((void *)vectors
+ 0x1000, __stubs_start
, __stubs_end
- __stubs_start
);
907 kuser_init(vectors_base
);
909 flush_icache_range(vectors
, vectors
+ PAGE_SIZE
* 2);
910 modify_domain(DOMAIN_USER
, DOMAIN_CLIENT
);
911 #else /* ifndef CONFIG_CPU_V7M */
913 * on V7-M there is no need to copy the vector table to a dedicated
914 * memory area. The address is configurable and so a table in the kernel