2 * linux/arch/arm26/kernel/traps.c
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)
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.
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.
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>
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>
31 #include <asm/atomic.h>
33 #include <asm/pgtable.h>
34 #include <asm/system.h>
35 #include <asm/uaccess.h>
36 #include <asm/unistd.h>
37 #include <linux/mutex.h>
41 extern void c_backtrace (unsigned long fp, int pmode);
42 extern void show_pte(struct mm_struct *mm, unsigned long addr);
44 const char *processor_modes[] = { "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" };
46 static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" "*bad reason*"};
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.
53 static int verify_stack(unsigned long sp)
55 if (sp < PAGE_OFFSET || (sp > (unsigned long)high_memory && high_memory != 0))
62 * Dump out the contents of some memory nicely...
64 static void dump_mem(const char *str, unsigned long bottom, unsigned long top)
66 unsigned long p = bottom & ~31;
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.
79 printk("(0x%08lx to 0x%08lx)\n", bottom, top);
81 for (p = bottom & ~31; p < top;) {
82 printk("%04lx: ", p & 0xffff);
84 for (i = 0; i < 8; i++, p += 4) {
87 if (p < bottom || p >= top)
90 __get_user(val, (unsigned long *)p);
100 static void dump_instr(struct pt_regs *regs)
102 unsigned long addr = instruction_pointer(regs);
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.
116 for (i = -4; i < 1; i++) {
117 unsigned int val, bad;
119 bad = __get_user(val, &((u32 *)addr)[i]);
122 printk(i == 0 ? "(%0*x) " : "%0*x ", width, val);
124 printk("bad PC value.");
133 /*static*/ void __dump_stack(struct task_struct *tsk, unsigned long sp)
135 dump_mem("Stack: ", sp, 8192+(unsigned long)task_stack_page(tsk));
138 void dump_stack(void)
140 #ifdef CONFIG_DEBUG_ERRORS
145 EXPORT_SYMBOL(dump_stack);
147 //FIXME - was a static fn
148 void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
153 printk("Backtrace: ");
156 printk("no frame pointer");
158 } else if (verify_stack(fp)) {
159 printk("invalid frame pointer 0x%08x", fp);
161 } else if (fp < (unsigned long)end_of_stack(tsk))
162 printk("frame pointer underflow");
166 c_backtrace(fp, processor_mode(regs));
169 /* FIXME - this is probably wrong.. */
170 void show_stack(struct task_struct *task, unsigned long *sp) {
171 dump_mem("Stack: ", (unsigned long)sp, 8192+(unsigned long)task_stack_page(task));
174 DEFINE_SPINLOCK(die_lock);
177 * This function is protected against re-entrancy.
179 NORET_TYPE void die(const char *str, struct pt_regs *regs, int err)
181 struct task_struct *tsk = current;
184 spin_lock_irq(&die_lock);
186 printk("Internal error: %s: %x\n", str, err);
187 printk("CPU: %d\n", smp_processor_id());
189 printk("Process %s (pid: %d[#%u], stack limit = 0x%p)\n",
190 current->comm, current->pid,
191 current->xid, end_of_stack(tsk));
193 if (!user_mode(regs) || in_interrupt()) {
194 __dump_stack(tsk, (unsigned long)(regs + 1));
195 dump_backtrace(regs, tsk);
199 spin_unlock_irq(&die_lock);
203 void die_if_kernel(const char *str, struct pt_regs *regs, int err)
211 static DEFINE_MUTEX(undef_mutex);
212 static int (*undef_hook)(struct pt_regs *);
214 int request_undef_hook(int (*fn)(struct pt_regs *))
218 mutex_lock(&undef_mutex);
219 if (undef_hook == NULL) {
223 mutex_unlock(&undef_mutex);
228 int release_undef_hook(int (*fn)(struct pt_regs *))
232 mutex_lock(&undef_mutex);
233 if (undef_hook == fn) {
237 mutex_unlock(&undef_mutex);
242 static int undefined_extension(struct pt_regs *regs, unsigned int op)
245 case 1: /* 0xde01 / 0x?7f001f0 */
246 ptrace_break(current, regs);
252 asmlinkage void do_undefinstr(struct pt_regs *regs)
259 pc = (unsigned long *)instruction_pointer(regs); /* strip PSR */
261 if (user_mode(regs)) {
264 get_user(instr, (u32 *)pc);
266 if ((instr & 0x0fff00ff) == 0x07f000f0 &&
267 undefined_extension(regs, (instr >> 8) & 255) == 0) {
272 if (undef_hook && undef_hook(regs) == 0) {
278 #ifdef CONFIG_DEBUG_USER
279 printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n",
280 current->comm, current->pid, pc);
284 current->thread.error_code = 0;
285 current->thread.trap_no = 6;
287 info.si_signo = SIGILL;
289 info.si_code = ILL_ILLOPC;
292 force_sig_info(SIGILL, &info, current);
294 die_if_kernel("Oops - undefined instruction", regs, 0);
297 asmlinkage void do_excpt(unsigned long address, struct pt_regs *regs, int mode)
301 #ifdef CONFIG_DEBUG_USER
302 printk(KERN_INFO "%s (%d): address exception: pc=%08lx\n",
303 current->comm, current->pid, instruction_pointer(regs));
307 current->thread.error_code = 0;
308 current->thread.trap_no = 11;
310 info.si_signo = SIGBUS;
312 info.si_code = BUS_ADRERR;
313 info.si_addr = (void *)address;
315 force_sig_info(SIGBUS, &info, current);
317 die_if_kernel("Oops - address exception", regs, mode);
320 asmlinkage void do_unexp_fiq (struct pt_regs *regs)
322 #ifndef CONFIG_IGNORE_FIQ
323 printk("Hmm. Unexpected FIQ received, but trying to continue\n");
324 printk("You may have a hardware problem...\n");
329 * bad_mode handles the impossible case in the vectors. If you see one of
330 * these, then it's extremely serious, and could mean you have buggy hardware.
331 * It never returns, and never tries to sync. We hope that we can at least
332 * dump out some state information...
334 asmlinkage void bad_mode(struct pt_regs *regs, int reason, int proc_mode)
336 unsigned int vectors = vectors_base();
340 printk(KERN_CRIT "Bad mode in %s handler detected: mode %s\n",
341 handler[reason<5?reason:4], processor_modes[proc_mode]);
344 * Dump out the vectors and stub routines. Maybe a better solution
345 * would be to dump them out only if we detect that they are corrupted.
347 dump_mem(KERN_CRIT "Vectors: ", vectors, vectors + 0x40);
348 dump_mem(KERN_CRIT "Stubs: ", vectors + 0x200, vectors + 0x4b8);
350 die("Oops", regs, 0);
355 static int bad_syscall(int n, struct pt_regs *regs)
357 struct thread_info *thread = current_thread_info();
360 if (current->personality != PER_LINUX && thread->exec_domain->handler) {
361 thread->exec_domain->handler(n, regs);
365 #ifdef CONFIG_DEBUG_USER
366 printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n",
367 current->pid, current->comm, n);
371 info.si_signo = SIGILL;
373 info.si_code = ILL_ILLTRP;
374 info.si_addr = (void *)instruction_pointer(regs) - 4;
376 force_sig_info(SIGILL, &info, current);
377 die_if_kernel("Oops", regs, n);
382 do_cache_op(unsigned long start, unsigned long end, int flags)
384 struct vm_area_struct *vma;
389 vma = find_vma(current->active_mm, start);
390 if (vma && vma->vm_start < end) {
391 if (start < vma->vm_start)
392 start = vma->vm_start;
393 if (end > vma->vm_end)
399 * Handle all unrecognised system calls.
400 * 0x9f0000 - 0x9fffff are some more esoteric system calls
402 #define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE)
403 asmlinkage int arm_syscall(int no, struct pt_regs *regs)
407 if ((no >> 16) != 0x9f)
408 return bad_syscall(no, regs);
410 switch (no & 0xffff) {
411 case 0: /* branch through 0 */
412 info.si_signo = SIGSEGV;
414 info.si_code = SEGV_MAPERR;
417 force_sig_info(SIGSEGV, &info, current);
419 die_if_kernel("branch through zero", regs, 0);
422 case NR(breakpoint): /* SWI BREAK_POINT */
423 ptrace_break(current, regs);
433 /* Calls 9f00xx..9f07ff are defined to return -ENOSYS
434 if not implemented, rather than raising SIGILL. This
435 way the calling program can gracefully determine whether
436 a feature is supported. */
441 #ifdef CONFIG_DEBUG_USER
443 * experience shows that these seem to indicate that
444 * something catastrophic has happened
446 printk("[%d] %s: arm syscall %d\n", current->pid, current->comm, no);
448 if (user_mode(regs)) {
450 c_backtrace(regs->ARM_fp, processor_mode(regs));
453 info.si_signo = SIGILL;
455 info.si_code = ILL_ILLTRP;
456 info.si_addr = (void *)instruction_pointer(regs) - 4;
458 force_sig_info(SIGILL, &info, current);
459 die_if_kernel("Oops", regs, no);
463 void __bad_xchg(volatile void *ptr, int size)
465 printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n",
466 __builtin_return_address(0), ptr, size);
471 * A data abort trap was taken, but we did not handle the instruction.
472 * Try to abort the user program, or panic if it was the kernel.
475 baddataabort(int code, unsigned long instr, struct pt_regs *regs)
477 unsigned long addr = instruction_pointer(regs);
480 #ifdef CONFIG_DEBUG_USER
481 printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n",
482 current->pid, current->comm, code, instr);
484 show_pte(current->mm, addr);
487 info.si_signo = SIGILL;
489 info.si_code = ILL_ILLOPC;
490 info.si_addr = (void *)addr;
492 force_sig_info(SIGILL, &info, current);
493 die_if_kernel("unknown data abort code", regs, instr);
496 volatile void __bug(const char *file, int line, void *data)
498 printk(KERN_CRIT"kernel BUG at %s:%d!", file, line);
500 printk(KERN_CRIT" - extra data = %p", data);
505 void __readwrite_bug(const char *fn)
507 printk("%s called, but not implemented", fn);
511 void __pte_error(const char *file, int line, unsigned long val)
513 printk("%s:%d: bad pte %08lx.\n", file, line, val);
516 void __pmd_error(const char *file, int line, unsigned long val)
518 printk("%s:%d: bad pmd %08lx.\n", file, line, val);
521 void __pgd_error(const char *file, int line, unsigned long val)
523 printk("%s:%d: bad pgd %08lx.\n", file, line, val);
526 asmlinkage void __div0(void)
528 printk("Division by zero in kernel.\n");
536 /* if that doesn't kill us, halt */
537 panic("Oops failed to kill thread");
540 void __init trap_init(void)
542 extern void __trap_init(unsigned long);
543 unsigned long base = vectors_base();
547 printk(KERN_DEBUG "Relocating machine vectors to 0x%08lx\n",