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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/delay.h>
25#include <linux/init.h>
26
27#include <asm/atomic.h>
28#include <asm/cacheflush.h>
29#include <asm/system.h>
30#include <asm/unistd.h>
31#include <asm/traps.h>
32#include <asm/unwind.h>
33#include <asm/tls.h>
34
35#include "ptrace.h"
36#include "signal.h"
37
38static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" };
39
40void *vectors_page;
41
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
53static void dump_mem(const char *, const char *, unsigned long, unsigned long);
54
55void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame)
56{
57#ifdef CONFIG_KALLSYMS
58 printk("[<%08lx>] (%pS) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from);
59#else
60 printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from);
61#endif
62
63 if (in_exception_text(where))
64 dump_mem("", "Exception stack", frame + 4, frame + 4 + sizeof(struct pt_regs));
65}
66
67#ifndef CONFIG_ARM_UNWIND
68
69
70
71
72
73static int verify_stack(unsigned long sp)
74{
75 if (sp < PAGE_OFFSET ||
76 (sp > (unsigned long)high_memory && high_memory != NULL))
77 return -EFAULT;
78
79 return 0;
80}
81#endif
82
83
84
85
86static void dump_mem(const char *lvl, const char *str, unsigned long bottom,
87 unsigned long top)
88{
89 unsigned long first;
90 mm_segment_t fs;
91 int i;
92
93
94
95
96
97
98 fs = get_fs();
99 set_fs(KERNEL_DS);
100
101 printk("%s%s(0x%08lx to 0x%08lx)\n", lvl, str, bottom, top);
102
103 for (first = bottom & ~31; first < top; first += 32) {
104 unsigned long p;
105 char str[sizeof(" 12345678") * 8 + 1];
106
107 memset(str, ' ', sizeof(str));
108 str[sizeof(str) - 1] = '\0';
109
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, " ????????");
117 }
118 }
119 printk("%s%04lx:%s\n", lvl, first & 0xffff, str);
120 }
121
122 set_fs(fs);
123}
124
125static void dump_instr(const char *lvl, struct pt_regs *regs)
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;
131 char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
132 int i;
133
134
135
136
137
138
139 fs = get_fs();
140 set_fs(KERNEL_DS);
141
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)
151 p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ",
152 width, val);
153 else {
154 p += sprintf(p, "bad PC value");
155 break;
156 }
157 }
158 printk("%sCode: %s\n", lvl, str);
159
160 set_fs(fs);
161}
162
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
169static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
170{
171 unsigned int fp, mode;
172 int ok = 1;
173
174 printk("Backtrace: ");
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
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;
196 } else if (fp < (unsigned long)end_of_stack(tsk))
197 printk("frame pointer underflow");
198 printk("\n");
199
200 if (ok)
201 c_backtrace(fp, mode);
202}
203#endif
204
205void dump_stack(void)
206{
207 dump_backtrace(NULL, NULL);
208}
209
210EXPORT_SYMBOL(dump_stack);
211
212void show_stack(struct task_struct *tsk, unsigned long *sp)
213{
214 dump_backtrace(NULL, tsk);
215 barrier();
216}
217
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
229static int __die(const char *str, int err, struct thread_info *thread, struct pt_regs *regs)
230{
231 struct task_struct *tsk = thread->task;
232 static int die_counter;
233 int ret;
234
235 printk(KERN_EMERG "Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n",
236 str, err, ++die_counter);
237 sysfs_printk_last_file();
238
239
240 ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, SIGSEGV);
241 if (ret == NOTIFY_STOP)
242 return ret;
243
244 print_modules();
245 __show_regs(regs);
246 printk(KERN_EMERG "Process %.*s (pid: %d, stack limit = 0x%p)\n",
247 TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1);
248
249 if (!user_mode(regs) || in_interrupt()) {
250 dump_mem(KERN_EMERG, "Stack: ", regs->ARM_sp,
251 THREAD_SIZE + (unsigned long)task_stack_page(tsk));
252 dump_backtrace(regs, tsk);
253 dump_instr(KERN_EMERG, regs);
254 }
255
256 return ret;
257}
258
259DEFINE_SPINLOCK(die_lock);
260
261
262
263
264void die(const char *str, struct pt_regs *regs, int err)
265{
266 struct thread_info *thread = current_thread_info();
267 int ret;
268
269 oops_enter();
270
271 spin_lock_irq(&die_lock);
272 console_verbose();
273 bust_spinlocks(1);
274 ret = __die(str, err, thread, regs);
275
276 if (regs && kexec_should_crash(thread->task))
277 crash_kexec(regs);
278
279 bust_spinlocks(0);
280 add_taint(TAINT_DIE);
281 spin_unlock_irq(&die_lock);
282 oops_exit();
283
284 if (in_interrupt())
285 panic("Fatal exception in interrupt");
286 if (panic_on_oops)
287 panic("Fatal exception");
288 if (ret != NOTIFY_STOP)
289 do_exit(SIGSEGV);
290}
291
292void arm_notify_die(const char *str, struct pt_regs *regs,
293 struct siginfo *info, unsigned long err, unsigned long trap)
294{
295 if (user_mode(regs)) {
296 current->thread.error_code = err;
297 current->thread.trap_no = trap;
298
299 force_sig_info(info->si_signo, info, current);
300 } else {
301 die(str, regs, err);
302 }
303}
304
305static LIST_HEAD(undef_hook);
306static DEFINE_SPINLOCK(undef_lock);
307
308void register_undef_hook(struct undef_hook *hook)
309{
310 unsigned long flags;
311
312 spin_lock_irqsave(&undef_lock, flags);
313 list_add(&hook->node, &undef_hook);
314 spin_unlock_irqrestore(&undef_lock, flags);
315}
316
317void unregister_undef_hook(struct undef_hook *hook)
318{
319 unsigned long flags;
320
321 spin_lock_irqsave(&undef_lock, flags);
322 list_del(&hook->node);
323 spin_unlock_irqrestore(&undef_lock, flags);
324}
325
326static int call_undef_hook(struct pt_regs *regs, unsigned int instr)
327{
328 struct undef_hook *hook;
329 unsigned long flags;
330 int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL;
331
332 spin_lock_irqsave(&undef_lock, flags);
333 list_for_each_entry(hook, &undef_hook, node)
334 if ((instr & hook->instr_mask) == hook->instr_val &&
335 (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val)
336 fn = hook->fn;
337 spin_unlock_irqrestore(&undef_lock, flags);
338
339 return fn ? fn(regs, instr) : 1;
340}
341
342asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
343{
344 unsigned int correction = thumb_mode(regs) ? 2 : 4;
345 unsigned int instr;
346 siginfo_t info;
347 void __user *pc;
348
349
350
351
352
353
354 regs->ARM_pc -= correction;
355
356 pc = (void __user *)instruction_pointer(regs);
357
358 if (processor_mode(regs) == SVC_MODE) {
359 instr = *(u32 *) pc;
360 } else if (thumb_mode(regs)) {
361 get_user(instr, (u16 __user *)pc);
362 } else {
363 get_user(instr, (u32 __user *)pc);
364 }
365
366 if (call_undef_hook(regs, instr) == 0)
367 return;
368
369#ifdef CONFIG_DEBUG_USER
370 if (user_debug & UDBG_UNDEFINED) {
371 printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n",
372 current->comm, task_pid_nr(current), pc);
373 dump_instr(KERN_INFO, regs);
374 }
375#endif
376
377 info.si_signo = SIGILL;
378 info.si_errno = 0;
379 info.si_code = ILL_ILLOPC;
380 info.si_addr = pc;
381
382 arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6);
383}
384
385asmlinkage void do_unexp_fiq (struct pt_regs *regs)
386{
387 printk("Hmm. Unexpected FIQ received, but trying to continue\n");
388 printk("You may have a hardware problem...\n");
389}
390
391
392
393
394
395
396
397asmlinkage void bad_mode(struct pt_regs *regs, int reason)
398{
399 console_verbose();
400
401 printk(KERN_CRIT "Bad mode in %s handler detected\n", handler[reason]);
402
403 die("Oops - bad mode", regs, 0);
404 local_irq_disable();
405 panic("bad mode");
406}
407
408static int bad_syscall(int n, struct pt_regs *regs)
409{
410 struct thread_info *thread = current_thread_info();
411 siginfo_t info;
412
413 if (current->personality != PER_LINUX &&
414 current->personality != PER_LINUX_32BIT &&
415 thread->exec_domain->handler) {
416 thread->exec_domain->handler(n, regs);
417 return regs->ARM_r0;
418 }
419
420#ifdef CONFIG_DEBUG_USER
421 if (user_debug & UDBG_SYSCALL) {
422 printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n",
423 task_pid_nr(current), current->comm, n);
424 dump_instr(KERN_ERR, regs);
425 }
426#endif
427
428 info.si_signo = SIGILL;
429 info.si_errno = 0;
430 info.si_code = ILL_ILLTRP;
431 info.si_addr = (void __user *)instruction_pointer(regs) -
432 (thumb_mode(regs) ? 2 : 4);
433
434 arm_notify_die("Oops - bad syscall", regs, &info, n, 0);
435
436 return regs->ARM_r0;
437}
438
439static inline void
440do_cache_op(unsigned long start, unsigned long end, int flags)
441{
442 struct mm_struct *mm = current->active_mm;
443 struct vm_area_struct *vma;
444
445 if (end < start || flags)
446 return;
447
448 down_read(&mm->mmap_sem);
449 vma = find_vma(mm, start);
450 if (vma && vma->vm_start < end) {
451 if (start < vma->vm_start)
452 start = vma->vm_start;
453 if (end > vma->vm_end)
454 end = vma->vm_end;
455
456 flush_cache_user_range(vma, start, end);
457 }
458 up_read(&mm->mmap_sem);
459}
460
461
462
463
464
465#define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE)
466asmlinkage int arm_syscall(int no, struct pt_regs *regs)
467{
468 struct thread_info *thread = current_thread_info();
469 siginfo_t info;
470
471 if ((no >> 16) != (__ARM_NR_BASE>> 16))
472 return bad_syscall(no, regs);
473
474 switch (no & 0xffff) {
475 case 0:
476 info.si_signo = SIGSEGV;
477 info.si_errno = 0;
478 info.si_code = SEGV_MAPERR;
479 info.si_addr = NULL;
480
481 arm_notify_die("branch through zero", regs, &info, 0, 0);
482 return 0;
483
484 case NR(breakpoint):
485 regs->ARM_pc -= thumb_mode(regs) ? 2 : 4;
486 ptrace_break(current, regs);
487 return regs->ARM_r0;
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503 case NR(cacheflush):
504 do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2);
505 return 0;
506
507 case NR(usr26):
508 if (!(elf_hwcap & HWCAP_26BIT))
509 break;
510 regs->ARM_cpsr &= ~MODE32_BIT;
511 return regs->ARM_r0;
512
513 case NR(usr32):
514 if (!(elf_hwcap & HWCAP_26BIT))
515 break;
516 regs->ARM_cpsr |= MODE32_BIT;
517 return regs->ARM_r0;
518
519 case NR(set_tls):
520 thread->tp_value = regs->ARM_r0;
521 if (tls_emu)
522 return 0;
523 if (has_tls_reg) {
524 asm ("mcr p15, 0, %0, c13, c0, 3"
525 : : "r" (regs->ARM_r0));
526 } else {
527
528
529
530
531
532
533 *((unsigned int *)0xffff0ff0) = regs->ARM_r0;
534 }
535 return 0;
536
537#ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG
538
539
540
541
542
543
544
545
546
547
548
549 case NR(cmpxchg):
550 for (;;) {
551 extern void do_DataAbort(unsigned long addr, unsigned int fsr,
552 struct pt_regs *regs);
553 unsigned long val;
554 unsigned long addr = regs->ARM_r2;
555 struct mm_struct *mm = current->mm;
556 pgd_t *pgd; pmd_t *pmd; pte_t *pte;
557 spinlock_t *ptl;
558
559 regs->ARM_cpsr &= ~PSR_C_BIT;
560 down_read(&mm->mmap_sem);
561 pgd = pgd_offset(mm, addr);
562 if (!pgd_present(*pgd))
563 goto bad_access;
564 pmd = pmd_offset(pgd, addr);
565 if (!pmd_present(*pmd))
566 goto bad_access;
567 pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
568 if (!pte_present(*pte) || !pte_dirty(*pte)) {
569 pte_unmap_unlock(pte, ptl);
570 goto bad_access;
571 }
572 val = *(unsigned long *)addr;
573 val -= regs->ARM_r0;
574 if (val == 0) {
575 *(unsigned long *)addr = regs->ARM_r1;
576 regs->ARM_cpsr |= PSR_C_BIT;
577 }
578 pte_unmap_unlock(pte, ptl);
579 up_read(&mm->mmap_sem);
580 return val;
581
582 bad_access:
583 up_read(&mm->mmap_sem);
584
585 do_DataAbort(addr, 15 + (1 << 11), regs);
586 }
587#endif
588
589 default:
590
591
592
593
594 if ((no & 0xffff) <= 0x7ff)
595 return -ENOSYS;
596 break;
597 }
598#ifdef CONFIG_DEBUG_USER
599
600
601
602
603 if (user_debug & UDBG_SYSCALL) {
604 printk("[%d] %s: arm syscall %d\n",
605 task_pid_nr(current), current->comm, no);
606 dump_instr("", regs);
607 if (user_mode(regs)) {
608 __show_regs(regs);
609 c_backtrace(regs->ARM_fp, processor_mode(regs));
610 }
611 }
612#endif
613 info.si_signo = SIGILL;
614 info.si_errno = 0;
615 info.si_code = ILL_ILLTRP;
616 info.si_addr = (void __user *)instruction_pointer(regs) -
617 (thumb_mode(regs) ? 2 : 4);
618
619 arm_notify_die("Oops - bad syscall(2)", regs, &info, no, 0);
620 return 0;
621}
622
623#ifdef CONFIG_TLS_REG_EMUL
624
625
626
627
628
629
630
631
632
633static int get_tp_trap(struct pt_regs *regs, unsigned int instr)
634{
635 int reg = (instr >> 12) & 15;
636 if (reg == 15)
637 return 1;
638 regs->uregs[reg] = current_thread_info()->tp_value;
639 regs->ARM_pc += 4;
640 return 0;
641}
642
643static struct undef_hook arm_mrc_hook = {
644 .instr_mask = 0x0fff0fff,
645 .instr_val = 0x0e1d0f70,
646 .cpsr_mask = PSR_T_BIT,
647 .cpsr_val = 0,
648 .fn = get_tp_trap,
649};
650
651static int __init arm_mrc_hook_init(void)
652{
653 register_undef_hook(&arm_mrc_hook);
654 return 0;
655}
656
657late_initcall(arm_mrc_hook_init);
658
659#endif
660
661void __bad_xchg(volatile void *ptr, int size)
662{
663 printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n",
664 __builtin_return_address(0), ptr, size);
665 BUG();
666}
667EXPORT_SYMBOL(__bad_xchg);
668
669
670
671
672
673asmlinkage void
674baddataabort(int code, unsigned long instr, struct pt_regs *regs)
675{
676 unsigned long addr = instruction_pointer(regs);
677 siginfo_t info;
678
679#ifdef CONFIG_DEBUG_USER
680 if (user_debug & UDBG_BADABORT) {
681 printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n",
682 task_pid_nr(current), current->comm, code, instr);
683 dump_instr(KERN_ERR, regs);
684 show_pte(current->mm, addr);
685 }
686#endif
687
688 info.si_signo = SIGILL;
689 info.si_errno = 0;
690 info.si_code = ILL_ILLOPC;
691 info.si_addr = (void __user *)addr;
692
693 arm_notify_die("unknown data abort code", regs, &info, instr, 0);
694}
695
696void __attribute__((noreturn)) __bug(const char *file, int line)
697{
698 printk(KERN_CRIT"kernel BUG at %s:%d!\n", file, line);
699 *(int *)0 = 0;
700
701
702 for (;;);
703}
704EXPORT_SYMBOL(__bug);
705
706void __readwrite_bug(const char *fn)
707{
708 printk("%s called, but not implemented\n", fn);
709 BUG();
710}
711EXPORT_SYMBOL(__readwrite_bug);
712
713void __pte_error(const char *file, int line, pte_t pte)
714{
715 printk("%s:%d: bad pte %08lx.\n", file, line, pte_val(pte));
716}
717
718void __pmd_error(const char *file, int line, pmd_t pmd)
719{
720 printk("%s:%d: bad pmd %08lx.\n", file, line, pmd_val(pmd));
721}
722
723void __pgd_error(const char *file, int line, pgd_t pgd)
724{
725 printk("%s:%d: bad pgd %08lx.\n", file, line, pgd_val(pgd));
726}
727
728asmlinkage void __div0(void)
729{
730 printk("Division by zero in kernel.\n");
731 dump_stack();
732}
733EXPORT_SYMBOL(__div0);
734
735void abort(void)
736{
737 BUG();
738
739
740 panic("Oops failed to kill thread");
741}
742EXPORT_SYMBOL(abort);
743
744void __init trap_init(void)
745{
746 return;
747}
748
749static void __init kuser_get_tls_init(unsigned long vectors)
750{
751
752
753
754
755 if (tls_emu || has_tls_reg)
756 memcpy((void *)vectors + 0xfe0, (void *)vectors + 0xfe8, 4);
757}
758
759void __init early_trap_init(void)
760{
761#if defined(CONFIG_CPU_USE_DOMAINS)
762 unsigned long vectors = CONFIG_VECTORS_BASE;
763#else
764 unsigned long vectors = (unsigned long)vectors_page;
765#endif
766 extern char __stubs_start[], __stubs_end[];
767 extern char __vectors_start[], __vectors_end[];
768 extern char __kuser_helper_start[], __kuser_helper_end[];
769 int kuser_sz = __kuser_helper_end - __kuser_helper_start;
770
771
772
773
774
775
776 memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start);
777 memcpy((void *)vectors + 0x200, __stubs_start, __stubs_end - __stubs_start);
778 memcpy((void *)vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz);
779
780
781
782
783 kuser_get_tls_init(vectors);
784
785
786
787
788
789 memcpy((void *)(vectors + KERN_SIGRETURN_CODE - CONFIG_VECTORS_BASE),
790 sigreturn_codes, sizeof(sigreturn_codes));
791 memcpy((void *)(vectors + KERN_RESTART_CODE - CONFIG_VECTORS_BASE),
792 syscall_restart_code, sizeof(syscall_restart_code));
793
794 flush_icache_range(vectors, vectors + PAGE_SIZE);
795 modify_domain(DOMAIN_USER, DOMAIN_CLIENT);
796}
797