ARM: 6879/1: fix personality test wrt usage of domain handlers
[deliverable/linux.git] / arch / arm / kernel / traps.c
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);
03a6e5bd 237 sysfs_printk_last_file();
a9221de6
RK
238
239 /* trap and error numbers are mostly meaningless on ARM */
240 ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, SIGSEGV);
241 if (ret == NOTIFY_STOP)
242 return ret;
243
1da177e4 244 print_modules();
652a12ef 245 __show_regs(regs);
e40c2ec6
RK
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);
1da177e4
LT
248
249 if (!user_mode(regs) || in_interrupt()) {
e40c2ec6 250 dump_mem(KERN_EMERG, "Stack: ", regs->ARM_sp,
32d39a93 251 THREAD_SIZE + (unsigned long)task_stack_page(tsk));
1da177e4 252 dump_backtrace(regs, tsk);
e40c2ec6 253 dump_instr(KERN_EMERG, regs);
1da177e4 254 }
a9221de6
RK
255
256 return ret;
d362979a 257}
1da177e4 258
2bbd7e9b 259static DEFINE_SPINLOCK(die_lock);
d362979a
RK
260
261/*
262 * This function is protected against re-entrancy.
263 */
a9221de6 264void die(const char *str, struct pt_regs *regs, int err)
d362979a
RK
265{
266 struct thread_info *thread = current_thread_info();
a9221de6 267 int ret;
d362979a 268
d9202429
RK
269 oops_enter();
270
d362979a 271 spin_lock_irq(&die_lock);
03a6e5bd 272 console_verbose();
d362979a 273 bust_spinlocks(1);
a9221de6
RK
274 ret = __die(str, err, thread, regs);
275
276 if (regs && kexec_should_crash(thread->task))
277 crash_kexec(regs);
278
1da177e4 279 bust_spinlocks(0);
bcdcd8e7 280 add_taint(TAINT_DIE);
1da177e4 281 spin_unlock_irq(&die_lock);
03a6e5bd 282 oops_exit();
31867499 283
d9202429
RK
284 if (in_interrupt())
285 panic("Fatal exception in interrupt");
cea6a4ba 286 if (panic_on_oops)
012c437d 287 panic("Fatal exception");
a9221de6
RK
288 if (ret != NOTIFY_STOP)
289 do_exit(SIGSEGV);
1da177e4
LT
290}
291
1eeb66a1
CH
292void arm_notify_die(const char *str, struct pt_regs *regs,
293 struct siginfo *info, unsigned long err, unsigned long trap)
1da177e4
LT
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{
109d89ca
RK
310 unsigned long flags;
311
312 spin_lock_irqsave(&undef_lock, flags);
1da177e4 313 list_add(&hook->node, &undef_hook);
109d89ca 314 spin_unlock_irqrestore(&undef_lock, flags);
1da177e4
LT
315}
316
317void unregister_undef_hook(struct undef_hook *hook)
318{
109d89ca
RK
319 unsigned long flags;
320
321 spin_lock_irqsave(&undef_lock, flags);
1da177e4 322 list_del(&hook->node);
109d89ca 323 spin_unlock_irqrestore(&undef_lock, flags);
1da177e4
LT
324}
325
b03a5b75
RK
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
7ab3f8d5 342asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
1da177e4
LT
343{
344 unsigned int correction = thumb_mode(regs) ? 2 : 4;
345 unsigned int instr;
1da177e4
LT
346 siginfo_t info;
347 void __user *pc;
348
349 /*
350 * According to the ARM ARM, PC is 2 or 4 bytes ahead,
351 * depending whether we're in Thumb mode or not.
352 * Correct this offset.
353 */
354 regs->ARM_pc -= correction;
355
356 pc = (void __user *)instruction_pointer(regs);
dfc544c7
DW
357
358 if (processor_mode(regs) == SVC_MODE) {
359 instr = *(u32 *) pc;
360 } else if (thumb_mode(regs)) {
1da177e4
LT
361 get_user(instr, (u16 __user *)pc);
362 } else {
363 get_user(instr, (u32 __user *)pc);
364 }
365
b03a5b75
RK
366 if (call_undef_hook(regs, instr) == 0)
367 return;
1da177e4
LT
368
369#ifdef CONFIG_DEBUG_USER
370 if (user_debug & UDBG_UNDEFINED) {
371 printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n",
19c5870c 372 current->comm, task_pid_nr(current), pc);
e40c2ec6 373 dump_instr(KERN_INFO, regs);
1da177e4
LT
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
1eeb66a1 382 arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6);
1da177e4
LT
383}
384
385asmlinkage void do_unexp_fiq (struct pt_regs *regs)
386{
1da177e4
LT
387 printk("Hmm. Unexpected FIQ received, but trying to continue\n");
388 printk("You may have a hardware problem...\n");
1da177e4
LT
389}
390
391/*
392 * bad_mode handles the impossible case in the vectors. If you see one of
393 * these, then it's extremely serious, and could mean you have buggy hardware.
394 * It never returns, and never tries to sync. We hope that we can at least
395 * dump out some state information...
396 */
ae0a846e 397asmlinkage void bad_mode(struct pt_regs *regs, int reason)
1da177e4
LT
398{
399 console_verbose();
400
ae0a846e 401 printk(KERN_CRIT "Bad mode in %s handler detected\n", handler[reason]);
1da177e4
LT
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
88b9ef45 413 if ((current->personality & PER_MASK) != PER_LINUX &&
a999cb04 414 thread->exec_domain->handler) {
1da177e4
LT
415 thread->exec_domain->handler(n, regs);
416 return regs->ARM_r0;
417 }
418
419#ifdef CONFIG_DEBUG_USER
420 if (user_debug & UDBG_SYSCALL) {
421 printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n",
19c5870c 422 task_pid_nr(current), current->comm, n);
e40c2ec6 423 dump_instr(KERN_ERR, regs);
1da177e4
LT
424 }
425#endif
426
427 info.si_signo = SIGILL;
428 info.si_errno = 0;
429 info.si_code = ILL_ILLTRP;
430 info.si_addr = (void __user *)instruction_pointer(regs) -
431 (thumb_mode(regs) ? 2 : 4);
432
1eeb66a1 433 arm_notify_die("Oops - bad syscall", regs, &info, n, 0);
1da177e4
LT
434
435 return regs->ARM_r0;
436}
437
438static inline void
439do_cache_op(unsigned long start, unsigned long end, int flags)
440{
aa45ee8f 441 struct mm_struct *mm = current->active_mm;
1da177e4
LT
442 struct vm_area_struct *vma;
443
444 if (end < start || flags)
445 return;
446
aa45ee8f
RK
447 down_read(&mm->mmap_sem);
448 vma = find_vma(mm, start);
1da177e4
LT
449 if (vma && vma->vm_start < end) {
450 if (start < vma->vm_start)
451 start = vma->vm_start;
452 if (end > vma->vm_end)
453 end = vma->vm_end;
454
455 flush_cache_user_range(vma, start, end);
456 }
aa45ee8f 457 up_read(&mm->mmap_sem);
1da177e4
LT
458}
459
460/*
461 * Handle all unrecognised system calls.
462 * 0x9f0000 - 0x9fffff are some more esoteric system calls
463 */
464#define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE)
465asmlinkage int arm_syscall(int no, struct pt_regs *regs)
466{
467 struct thread_info *thread = current_thread_info();
468 siginfo_t info;
469
3f2829a3 470 if ((no >> 16) != (__ARM_NR_BASE>> 16))
1da177e4
LT
471 return bad_syscall(no, regs);
472
473 switch (no & 0xffff) {
474 case 0: /* branch through 0 */
475 info.si_signo = SIGSEGV;
476 info.si_errno = 0;
477 info.si_code = SEGV_MAPERR;
478 info.si_addr = NULL;
479
1eeb66a1 480 arm_notify_die("branch through zero", regs, &info, 0, 0);
1da177e4
LT
481 return 0;
482
483 case NR(breakpoint): /* SWI BREAK_POINT */
484 regs->ARM_pc -= thumb_mode(regs) ? 2 : 4;
485 ptrace_break(current, regs);
486 return regs->ARM_r0;
487
488 /*
489 * Flush a region from virtual address 'r0' to virtual address 'r1'
490 * _exclusive_. There is no alignment requirement on either address;
491 * user space does not need to know the hardware cache layout.
492 *
493 * r2 contains flags. It should ALWAYS be passed as ZERO until it
494 * is defined to be something else. For now we ignore it, but may
495 * the fires of hell burn in your belly if you break this rule. ;)
496 *
497 * (at a later date, we may want to allow this call to not flush
498 * various aspects of the cache. Passing '0' will guarantee that
499 * everything necessary gets flushed to maintain consistency in
500 * the specified region).
501 */
502 case NR(cacheflush):
503 do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2);
504 return 0;
505
506 case NR(usr26):
507 if (!(elf_hwcap & HWCAP_26BIT))
508 break;
509 regs->ARM_cpsr &= ~MODE32_BIT;
510 return regs->ARM_r0;
511
512 case NR(usr32):
513 if (!(elf_hwcap & HWCAP_26BIT))
514 break;
515 regs->ARM_cpsr |= MODE32_BIT;
516 return regs->ARM_r0;
517
518 case NR(set_tls):
519 thread->tp_value = regs->ARM_r0;
f159f4ed
TL
520 if (tls_emu)
521 return 0;
522 if (has_tls_reg) {
523 asm ("mcr p15, 0, %0, c13, c0, 3"
524 : : "r" (regs->ARM_r0));
525 } else {
526 /*
527 * User space must never try to access this directly.
528 * Expect your app to break eventually if you do so.
529 * The user helper at 0xffff0fe0 must be used instead.
530 * (see entry-armv.S for details)
531 */
532 *((unsigned int *)0xffff0ff0) = regs->ARM_r0;
533 }
1da177e4
LT
534 return 0;
535
dcef1f63
NP
536#ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG
537 /*
538 * Atomically store r1 in *r2 if *r2 is equal to r0 for user space.
539 * Return zero in r0 if *MEM was changed or non-zero if no exchange
540 * happened. Also set the user C flag accordingly.
541 * If access permissions have to be fixed up then non-zero is
542 * returned and the operation has to be re-attempted.
543 *
544 * *NOTE*: This is a ghost syscall private to the kernel. Only the
545 * __kuser_cmpxchg code in entry-armv.S should be aware of its
546 * existence. Don't ever use this from user code.
547 */
cc20d429 548 case NR(cmpxchg):
b49c0f24 549 for (;;) {
dcef1f63
NP
550 extern void do_DataAbort(unsigned long addr, unsigned int fsr,
551 struct pt_regs *regs);
552 unsigned long val;
553 unsigned long addr = regs->ARM_r2;
554 struct mm_struct *mm = current->mm;
555 pgd_t *pgd; pmd_t *pmd; pte_t *pte;
69b04754 556 spinlock_t *ptl;
dcef1f63
NP
557
558 regs->ARM_cpsr &= ~PSR_C_BIT;
69b04754 559 down_read(&mm->mmap_sem);
dcef1f63
NP
560 pgd = pgd_offset(mm, addr);
561 if (!pgd_present(*pgd))
562 goto bad_access;
563 pmd = pmd_offset(pgd, addr);
564 if (!pmd_present(*pmd))
565 goto bad_access;
69b04754 566 pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
2ce9804f 567 if (!pte_present(*pte) || !pte_dirty(*pte)) {
69b04754 568 pte_unmap_unlock(pte, ptl);
dcef1f63 569 goto bad_access;
69b04754 570 }
dcef1f63
NP
571 val = *(unsigned long *)addr;
572 val -= regs->ARM_r0;
573 if (val == 0) {
574 *(unsigned long *)addr = regs->ARM_r1;
575 regs->ARM_cpsr |= PSR_C_BIT;
576 }
69b04754
HD
577 pte_unmap_unlock(pte, ptl);
578 up_read(&mm->mmap_sem);
dcef1f63
NP
579 return val;
580
581 bad_access:
69b04754 582 up_read(&mm->mmap_sem);
74f88494 583 /* simulate a write access fault */
dcef1f63 584 do_DataAbort(addr, 15 + (1 << 11), regs);
dcef1f63
NP
585 }
586#endif
587
1da177e4
LT
588 default:
589 /* Calls 9f00xx..9f07ff are defined to return -ENOSYS
590 if not implemented, rather than raising SIGILL. This
591 way the calling program can gracefully determine whether
592 a feature is supported. */
bfd2e29f 593 if ((no & 0xffff) <= 0x7ff)
1da177e4
LT
594 return -ENOSYS;
595 break;
596 }
597#ifdef CONFIG_DEBUG_USER
598 /*
599 * experience shows that these seem to indicate that
600 * something catastrophic has happened
601 */
602 if (user_debug & UDBG_SYSCALL) {
603 printk("[%d] %s: arm syscall %d\n",
19c5870c 604 task_pid_nr(current), current->comm, no);
e40c2ec6 605 dump_instr("", regs);
1da177e4 606 if (user_mode(regs)) {
652a12ef 607 __show_regs(regs);
1da177e4
LT
608 c_backtrace(regs->ARM_fp, processor_mode(regs));
609 }
610 }
611#endif
612 info.si_signo = SIGILL;
613 info.si_errno = 0;
614 info.si_code = ILL_ILLTRP;
615 info.si_addr = (void __user *)instruction_pointer(regs) -
616 (thumb_mode(regs) ? 2 : 4);
617
1eeb66a1 618 arm_notify_die("Oops - bad syscall(2)", regs, &info, no, 0);
1da177e4
LT
619 return 0;
620}
621
4b0e07a5 622#ifdef CONFIG_TLS_REG_EMUL
2d2669b6
NP
623
624/*
625 * We might be running on an ARMv6+ processor which should have the TLS
4b0e07a5
NP
626 * register but for some reason we can't use it, or maybe an SMP system
627 * using a pre-ARMv6 processor (there are apparently a few prototypes like
628 * that in existence) and therefore access to that register must be
629 * emulated.
2d2669b6
NP
630 */
631
632static int get_tp_trap(struct pt_regs *regs, unsigned int instr)
633{
634 int reg = (instr >> 12) & 15;
635 if (reg == 15)
636 return 1;
637 regs->uregs[reg] = current_thread_info()->tp_value;
638 regs->ARM_pc += 4;
639 return 0;
640}
641
642static struct undef_hook arm_mrc_hook = {
643 .instr_mask = 0x0fff0fff,
644 .instr_val = 0x0e1d0f70,
645 .cpsr_mask = PSR_T_BIT,
646 .cpsr_val = 0,
647 .fn = get_tp_trap,
648};
649
650static int __init arm_mrc_hook_init(void)
651{
652 register_undef_hook(&arm_mrc_hook);
653 return 0;
654}
655
656late_initcall(arm_mrc_hook_init);
657
658#endif
659
1da177e4
LT
660void __bad_xchg(volatile void *ptr, int size)
661{
662 printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n",
663 __builtin_return_address(0), ptr, size);
664 BUG();
665}
666EXPORT_SYMBOL(__bad_xchg);
667
668/*
669 * A data abort trap was taken, but we did not handle the instruction.
670 * Try to abort the user program, or panic if it was the kernel.
671 */
672asmlinkage void
673baddataabort(int code, unsigned long instr, struct pt_regs *regs)
674{
675 unsigned long addr = instruction_pointer(regs);
676 siginfo_t info;
677
678#ifdef CONFIG_DEBUG_USER
679 if (user_debug & UDBG_BADABORT) {
680 printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n",
19c5870c 681 task_pid_nr(current), current->comm, code, instr);
e40c2ec6 682 dump_instr(KERN_ERR, regs);
1da177e4
LT
683 show_pte(current->mm, addr);
684 }
685#endif
686
687 info.si_signo = SIGILL;
688 info.si_errno = 0;
689 info.si_code = ILL_ILLOPC;
690 info.si_addr = (void __user *)addr;
691
1eeb66a1 692 arm_notify_die("unknown data abort code", regs, &info, instr, 0);
1da177e4
LT
693}
694
7174d852 695void __attribute__((noreturn)) __bug(const char *file, int line)
1da177e4 696{
7174d852 697 printk(KERN_CRIT"kernel BUG at %s:%d!\n", file, line);
1da177e4 698 *(int *)0 = 0;
6a1ced59
CM
699
700 /* Avoid "noreturn function does return" */
701 for (;;);
1da177e4
LT
702}
703EXPORT_SYMBOL(__bug);
704
705void __readwrite_bug(const char *fn)
706{
707 printk("%s called, but not implemented\n", fn);
708 BUG();
709}
710EXPORT_SYMBOL(__readwrite_bug);
711
69529c0e 712void __pte_error(const char *file, int line, pte_t pte)
1da177e4 713{
29a38193 714 printk("%s:%d: bad pte %08llx.\n", file, line, (long long)pte_val(pte));
1da177e4
LT
715}
716
69529c0e 717void __pmd_error(const char *file, int line, pmd_t pmd)
1da177e4 718{
29a38193 719 printk("%s:%d: bad pmd %08llx.\n", file, line, (long long)pmd_val(pmd));
1da177e4
LT
720}
721
69529c0e 722void __pgd_error(const char *file, int line, pgd_t pgd)
1da177e4 723{
29a38193 724 printk("%s:%d: bad pgd %08llx.\n", file, line, (long long)pgd_val(pgd));
1da177e4
LT
725}
726
727asmlinkage void __div0(void)
728{
729 printk("Division by zero in kernel.\n");
730 dump_stack();
731}
732EXPORT_SYMBOL(__div0);
733
734void abort(void)
735{
736 BUG();
737
738 /* if that doesn't kill us, halt */
739 panic("Oops failed to kill thread");
740}
741EXPORT_SYMBOL(abort);
742
743void __init trap_init(void)
5cbad0eb
JW
744{
745 return;
746}
747
f159f4ed
TL
748static void __init kuser_get_tls_init(unsigned long vectors)
749{
750 /*
751 * vectors + 0xfe0 = __kuser_get_tls
752 * vectors + 0xfe8 = hardware TLS instruction at 0xffff0fe8
753 */
754 if (tls_emu || has_tls_reg)
755 memcpy((void *)vectors + 0xfe0, (void *)vectors + 0xfe8, 4);
756}
757
5cbad0eb 758void __init early_trap_init(void)
1da177e4 759{
247055aa 760#if defined(CONFIG_CPU_USE_DOMAINS)
c760fc19 761 unsigned long vectors = CONFIG_VECTORS_BASE;
247055aa
CM
762#else
763 unsigned long vectors = (unsigned long)vectors_page;
764#endif
7933523d
RK
765 extern char __stubs_start[], __stubs_end[];
766 extern char __vectors_start[], __vectors_end[];
2d2669b6
NP
767 extern char __kuser_helper_start[], __kuser_helper_end[];
768 int kuser_sz = __kuser_helper_end - __kuser_helper_start;
1da177e4 769
7933523d 770 /*
2d2669b6
NP
771 * Copy the vectors, stubs and kuser helpers (in entry-armv.S)
772 * into the vector page, mapped at 0xffff0000, and ensure these
773 * are visible to the instruction stream.
7933523d 774 */
c760fc19
HC
775 memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start);
776 memcpy((void *)vectors + 0x200, __stubs_start, __stubs_end - __stubs_start);
777 memcpy((void *)vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz);
e00d349e 778
f159f4ed
TL
779 /*
780 * Do processor specific fixups for the kuser helpers
781 */
782 kuser_get_tls_init(vectors);
783
e00d349e
RK
784 /*
785 * Copy signal return handlers into the vector page, and
786 * set sigreturn to be a pointer to these.
787 */
247055aa
CM
788 memcpy((void *)(vectors + KERN_SIGRETURN_CODE - CONFIG_VECTORS_BASE),
789 sigreturn_codes, sizeof(sigreturn_codes));
790 memcpy((void *)(vectors + KERN_RESTART_CODE - CONFIG_VECTORS_BASE),
791 syscall_restart_code, sizeof(syscall_restart_code));
e00d349e 792
c760fc19 793 flush_icache_range(vectors, vectors + PAGE_SIZE);
1da177e4
LT
794 modify_domain(DOMAIN_USER, DOMAIN_CLIENT);
795}
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