Remove 'type' argument from access_ok() function
[linux-2.6-block.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 21#include <linux/kdebug.h>
eb0146da 22#include <linux/kprobes.h>
a9221de6
RK
23#include <linux/module.h>
24#include <linux/kexec.h>
87e040b6 25#include <linux/bug.h>
a9221de6 26#include <linux/delay.h>
1da177e4 27#include <linux/init.h>
3f07c014 28#include <linux/sched/signal.h>
b17b0153 29#include <linux/sched/debug.h>
68db0cf1 30#include <linux/sched/task_stack.h>
c0e7f7ee 31#include <linux/irq.h>
1da177e4 32
60063497 33#include <linux/atomic.h>
1da177e4 34#include <asm/cacheflush.h>
5a567d78 35#include <asm/exception.h>
1da177e4
LT
36#include <asm/unistd.h>
37#include <asm/traps.h>
49432d4a 38#include <asm/ptrace.h>
bff595c1 39#include <asm/unwind.h>
f159f4ed 40#include <asm/tls.h>
9f97da78 41#include <asm/system_misc.h>
a79a0cb1 42#include <asm/opcodes.h>
1da177e4 43
49432d4a 44
29c350bf
RK
45static const char *handler[]= {
46 "prefetch abort",
47 "data abort",
48 "address exception",
49 "interrupt",
50 "undefined instruction",
51};
1da177e4 52
247055aa
CM
53void *vectors_page;
54
1da177e4
LT
55#ifdef CONFIG_DEBUG_USER
56unsigned int user_debug;
57
58static int __init user_debug_setup(char *str)
59{
60 get_option(&str, &user_debug);
61 return 1;
62}
63__setup("user_debug=", user_debug_setup);
64#endif
65
e40c2ec6 66static void dump_mem(const char *, const char *, unsigned long, unsigned long);
7ab3f8d5 67
7ab3f8d5 68void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame)
1da177e4
LT
69{
70#ifdef CONFIG_KALLSYMS
ef41b5c9 71 printk("[<%08lx>] (%ps) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from);
1da177e4
LT
72#else
73 printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from);
74#endif
7ab3f8d5 75
c6089061 76 if (in_entry_text(from))
e40c2ec6 77 dump_mem("", "Exception stack", frame + 4, frame + 4 + sizeof(struct pt_regs));
1da177e4
LT
78}
79
24c66dfd
RK
80void dump_backtrace_stm(u32 *stack, u32 instruction)
81{
82 char str[80], *p;
83 unsigned int x;
84 int reg;
85
86 for (reg = 10, x = 0, p = str; reg >= 0; reg--) {
87 if (instruction & BIT(reg)) {
88 p += sprintf(p, " r%d:%08x", reg, *stack--);
89 if (++x == 6) {
90 x = 0;
91 p = str;
92 printk("%s\n", str);
93 }
94 }
95 }
96 if (p != str)
97 printk("%s\n", str);
98}
99
bff595c1 100#ifndef CONFIG_ARM_UNWIND
1da177e4
LT
101/*
102 * Stack pointers should always be within the kernels view of
103 * physical memory. If it is not there, then we can't dump
104 * out any information relating to the stack.
105 */
106static int verify_stack(unsigned long sp)
107{
09d9bae0
RK
108 if (sp < PAGE_OFFSET ||
109 (sp > (unsigned long)high_memory && high_memory != NULL))
1da177e4
LT
110 return -EFAULT;
111
112 return 0;
113}
bff595c1 114#endif
1da177e4
LT
115
116/*
117 * Dump out the contents of some memory nicely...
118 */
e40c2ec6
RK
119static void dump_mem(const char *lvl, const char *str, unsigned long bottom,
120 unsigned long top)
1da177e4 121{
d191fe09 122 unsigned long first;
1da177e4
LT
123 mm_segment_t fs;
124 int i;
125
126 /*
127 * We need to switch to kernel mode so that we can use __get_user
128 * to safely read from kernel space. Note that we now dump the
129 * code first, just in case the backtrace kills us.
130 */
131 fs = get_fs();
132 set_fs(KERNEL_DS);
133
e40c2ec6 134 printk("%s%s(0x%08lx to 0x%08lx)\n", lvl, str, bottom, top);
1da177e4 135
d191fe09
RK
136 for (first = bottom & ~31; first < top; first += 32) {
137 unsigned long p;
138 char str[sizeof(" 12345678") * 8 + 1];
1da177e4 139
d191fe09
RK
140 memset(str, ' ', sizeof(str));
141 str[sizeof(str) - 1] = '\0';
1da177e4 142
d191fe09
RK
143 for (p = first, i = 0; i < 8 && p < top; i++, p += 4) {
144 if (p >= bottom && p < top) {
145 unsigned long val;
146 if (__get_user(val, (unsigned long *)p) == 0)
147 sprintf(str + i * 9, " %08lx", val);
148 else
149 sprintf(str + i * 9, " ????????");
1da177e4
LT
150 }
151 }
e40c2ec6 152 printk("%s%04lx:%s\n", lvl, first & 0xffff, str);
1da177e4
LT
153 }
154
155 set_fs(fs);
156}
157
b9dd05c7 158static void __dump_instr(const char *lvl, struct pt_regs *regs)
1da177e4
LT
159{
160 unsigned long addr = instruction_pointer(regs);
161 const int thumb = thumb_mode(regs);
162 const int width = thumb ? 4 : 8;
d191fe09 163 char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
1da177e4
LT
164 int i;
165
166 /*
b9dd05c7
MR
167 * Note that we now dump the code first, just in case the backtrace
168 * kills us.
1da177e4 169 */
1da177e4 170
a9011580 171 for (i = -4; i < 1 + !!thumb; i++) {
1da177e4
LT
172 unsigned int val, bad;
173
174 if (thumb)
b9dd05c7 175 bad = get_user(val, &((u16 *)addr)[i]);
1da177e4 176 else
b9dd05c7 177 bad = get_user(val, &((u32 *)addr)[i]);
1da177e4
LT
178
179 if (!bad)
d191fe09
RK
180 p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ",
181 width, val);
1da177e4 182 else {
d191fe09 183 p += sprintf(p, "bad PC value");
1da177e4
LT
184 break;
185 }
186 }
e40c2ec6 187 printk("%sCode: %s\n", lvl, str);
b9dd05c7 188}
1da177e4 189
b9dd05c7
MR
190static void dump_instr(const char *lvl, struct pt_regs *regs)
191{
192 mm_segment_t fs;
193
194 if (!user_mode(regs)) {
195 fs = get_fs();
196 set_fs(KERNEL_DS);
197 __dump_instr(lvl, regs);
198 set_fs(fs);
199 } else {
200 __dump_instr(lvl, regs);
201 }
1da177e4
LT
202}
203
bff595c1
CM
204#ifdef CONFIG_ARM_UNWIND
205static inline void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
206{
207 unwind_backtrace(regs, tsk);
208}
209#else
1da177e4
LT
210static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
211{
67a94c23 212 unsigned int fp, mode;
1da177e4
LT
213 int ok = 1;
214
215 printk("Backtrace: ");
67a94c23
CM
216
217 if (!tsk)
218 tsk = current;
219
220 if (regs) {
49432d4a 221 fp = frame_pointer(regs);
67a94c23
CM
222 mode = processor_mode(regs);
223 } else if (tsk != current) {
224 fp = thread_saved_fp(tsk);
225 mode = 0x10;
226 } else {
227 asm("mov %0, fp" : "=r" (fp) : : "cc");
228 mode = 0x10;
229 }
230
1da177e4 231 if (!fp) {
4ed89f22 232 pr_cont("no frame pointer");
1da177e4
LT
233 ok = 0;
234 } else if (verify_stack(fp)) {
4ed89f22 235 pr_cont("invalid frame pointer 0x%08x", fp);
1da177e4 236 ok = 0;
55205823 237 } else if (fp < (unsigned long)end_of_stack(tsk))
4ed89f22
RK
238 pr_cont("frame pointer underflow");
239 pr_cont("\n");
1da177e4
LT
240
241 if (ok)
67a94c23 242 c_backtrace(fp, mode);
1da177e4 243}
bff595c1 244#endif
1da177e4 245
1da177e4
LT
246void show_stack(struct task_struct *tsk, unsigned long *sp)
247{
67a94c23 248 dump_backtrace(NULL, tsk);
1da177e4
LT
249 barrier();
250}
251
d9202429
RK
252#ifdef CONFIG_PREEMPT
253#define S_PREEMPT " PREEMPT"
254#else
255#define S_PREEMPT ""
256#endif
257#ifdef CONFIG_SMP
258#define S_SMP " SMP"
259#else
260#define S_SMP ""
261#endif
8211ca65
RK
262#ifdef CONFIG_THUMB2_KERNEL
263#define S_ISA " THUMB2"
264#else
265#define S_ISA " ARM"
266#endif
d9202429 267
02df19b4 268static int __die(const char *str, int err, struct pt_regs *regs)
1da177e4 269{
02df19b4 270 struct task_struct *tsk = current;
1da177e4 271 static int die_counter;
a9221de6 272 int ret;
1da177e4 273
4ed89f22
RK
274 pr_emerg("Internal error: %s: %x [#%d]" S_PREEMPT S_SMP S_ISA "\n",
275 str, err, ++die_counter);
a9221de6
RK
276
277 /* trap and error numbers are mostly meaningless on ARM */
278 ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, SIGSEGV);
279 if (ret == NOTIFY_STOP)
02df19b4 280 return 1;
a9221de6 281
1da177e4 282 print_modules();
652a12ef 283 __show_regs(regs);
4ed89f22
RK
284 pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n",
285 TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), end_of_stack(tsk));
1da177e4
LT
286
287 if (!user_mode(regs) || in_interrupt()) {
e40c2ec6 288 dump_mem(KERN_EMERG, "Stack: ", regs->ARM_sp,
32d39a93 289 THREAD_SIZE + (unsigned long)task_stack_page(tsk));
1da177e4 290 dump_backtrace(regs, tsk);
e40c2ec6 291 dump_instr(KERN_EMERG, regs);
1da177e4 292 }
a9221de6 293
02df19b4 294 return 0;
d362979a 295}
1da177e4 296
02df19b4
RV
297static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
298static int die_owner = -1;
299static unsigned int die_nest_count;
d362979a 300
02df19b4 301static unsigned long oops_begin(void)
d362979a 302{
02df19b4
RV
303 int cpu;
304 unsigned long flags;
d362979a 305
d9202429
RK
306 oops_enter();
307
02df19b4
RV
308 /* racy, but better than risking deadlock. */
309 raw_local_irq_save(flags);
310 cpu = smp_processor_id();
311 if (!arch_spin_trylock(&die_lock)) {
312 if (cpu == die_owner)
313 /* nested oops. should stop eventually */;
314 else
315 arch_spin_lock(&die_lock);
316 }
317 die_nest_count++;
318 die_owner = cpu;
03a6e5bd 319 console_verbose();
d362979a 320 bust_spinlocks(1);
02df19b4
RV
321 return flags;
322}
a9221de6 323
02df19b4
RV
324static void oops_end(unsigned long flags, struct pt_regs *regs, int signr)
325{
326 if (regs && kexec_should_crash(current))
a9221de6
RK
327 crash_kexec(regs);
328
1da177e4 329 bust_spinlocks(0);
02df19b4 330 die_owner = -1;
373d4d09 331 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
02df19b4
RV
332 die_nest_count--;
333 if (!die_nest_count)
334 /* Nest count reaches zero, release the lock. */
335 arch_spin_unlock(&die_lock);
336 raw_local_irq_restore(flags);
03a6e5bd 337 oops_exit();
31867499 338
d9202429
RK
339 if (in_interrupt())
340 panic("Fatal exception in interrupt");
cea6a4ba 341 if (panic_on_oops)
012c437d 342 panic("Fatal exception");
02df19b4
RV
343 if (signr)
344 do_exit(signr);
345}
346
347/*
348 * This function is protected against re-entrancy.
349 */
350void die(const char *str, struct pt_regs *regs, int err)
351{
352 enum bug_trap_type bug_type = BUG_TRAP_TYPE_NONE;
353 unsigned long flags = oops_begin();
354 int sig = SIGSEGV;
355
356 if (!user_mode(regs))
357 bug_type = report_bug(regs->ARM_pc, regs);
358 if (bug_type != BUG_TRAP_TYPE_NONE)
359 str = "Oops - BUG";
360
361 if (__die(str, err, regs))
362 sig = 0;
363
364 oops_end(flags, regs, sig);
1da177e4
LT
365}
366
1eeb66a1 367void arm_notify_die(const char *str, struct pt_regs *regs,
05e792e3
EB
368 int signo, int si_code, void __user *addr,
369 unsigned long err, unsigned long trap)
1da177e4
LT
370{
371 if (user_mode(regs)) {
372 current->thread.error_code = err;
373 current->thread.trap_no = trap;
374
05e792e3 375 force_sig_fault(signo, si_code, addr, current);
1da177e4
LT
376 } else {
377 die(str, regs, err);
378 }
379}
380
87e040b6
SG
381#ifdef CONFIG_GENERIC_BUG
382
383int is_valid_bugaddr(unsigned long pc)
384{
385#ifdef CONFIG_THUMB2_KERNEL
63328070
BD
386 u16 bkpt;
387 u16 insn = __opcode_to_mem_thumb16(BUG_INSTR_VALUE);
87e040b6 388#else
63328070
BD
389 u32 bkpt;
390 u32 insn = __opcode_to_mem_arm(BUG_INSTR_VALUE);
87e040b6
SG
391#endif
392
393 if (probe_kernel_address((unsigned *)pc, bkpt))
394 return 0;
395
63328070 396 return bkpt == insn;
87e040b6
SG
397}
398
399#endif
400
1da177e4 401static LIST_HEAD(undef_hook);
bd31b859 402static DEFINE_RAW_SPINLOCK(undef_lock);
1da177e4
LT
403
404void register_undef_hook(struct undef_hook *hook)
405{
109d89ca
RK
406 unsigned long flags;
407
bd31b859 408 raw_spin_lock_irqsave(&undef_lock, flags);
1da177e4 409 list_add(&hook->node, &undef_hook);
bd31b859 410 raw_spin_unlock_irqrestore(&undef_lock, flags);
1da177e4
LT
411}
412
413void unregister_undef_hook(struct undef_hook *hook)
414{
109d89ca
RK
415 unsigned long flags;
416
bd31b859 417 raw_spin_lock_irqsave(&undef_lock, flags);
1da177e4 418 list_del(&hook->node);
bd31b859 419 raw_spin_unlock_irqrestore(&undef_lock, flags);
1da177e4
LT
420}
421
eb0146da
MH
422static nokprobe_inline
423int call_undef_hook(struct pt_regs *regs, unsigned int instr)
b03a5b75
RK
424{
425 struct undef_hook *hook;
426 unsigned long flags;
427 int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL;
428
bd31b859 429 raw_spin_lock_irqsave(&undef_lock, flags);
b03a5b75
RK
430 list_for_each_entry(hook, &undef_hook, node)
431 if ((instr & hook->instr_mask) == hook->instr_val &&
432 (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val)
433 fn = hook->fn;
bd31b859 434 raw_spin_unlock_irqrestore(&undef_lock, flags);
b03a5b75
RK
435
436 return fn ? fn(regs, instr) : 1;
437}
438
c6089061 439asmlinkage void do_undefinstr(struct pt_regs *regs)
1da177e4 440{
1da177e4 441 unsigned int instr;
1da177e4
LT
442 void __user *pc;
443
1da177e4 444 pc = (void __user *)instruction_pointer(regs);
dfc544c7
DW
445
446 if (processor_mode(regs) == SVC_MODE) {
592201a9
JM
447#ifdef CONFIG_THUMB2_KERNEL
448 if (thumb_mode(regs)) {
a79a0cb1 449 instr = __mem_to_opcode_thumb16(((u16 *)pc)[0]);
592201a9 450 if (is_wide_instruction(instr)) {
a79a0cb1
BD
451 u16 inst2;
452 inst2 = __mem_to_opcode_thumb16(((u16 *)pc)[1]);
453 instr = __opcode_thumb32_compose(instr, inst2);
592201a9
JM
454 }
455 } else
456#endif
a79a0cb1 457 instr = __mem_to_opcode_arm(*(u32 *) pc);
dfc544c7 458 } else if (thumb_mode(regs)) {
2b2040af
WD
459 if (get_user(instr, (u16 __user *)pc))
460 goto die_sig;
a79a0cb1 461 instr = __mem_to_opcode_thumb16(instr);
592201a9
JM
462 if (is_wide_instruction(instr)) {
463 unsigned int instr2;
2b2040af
WD
464 if (get_user(instr2, (u16 __user *)pc+1))
465 goto die_sig;
a79a0cb1
BD
466 instr2 = __mem_to_opcode_thumb16(instr2);
467 instr = __opcode_thumb32_compose(instr, instr2);
592201a9 468 }
d6cd9894
TK
469 } else {
470 if (get_user(instr, (u32 __user *)pc))
471 goto die_sig;
a79a0cb1 472 instr = __mem_to_opcode_arm(instr);
1da177e4
LT
473 }
474
b03a5b75
RK
475 if (call_undef_hook(regs, instr) == 0)
476 return;
1da177e4 477
2b2040af 478die_sig:
1da177e4
LT
479#ifdef CONFIG_DEBUG_USER
480 if (user_debug & UDBG_UNDEFINED) {
4ed89f22 481 pr_info("%s (%d): undefined instruction: pc=%p\n",
19c5870c 482 current->comm, task_pid_nr(current), pc);
b5b6b5f5 483 __show_regs(regs);
e40c2ec6 484 dump_instr(KERN_INFO, regs);
1da177e4
LT
485 }
486#endif
05e792e3
EB
487 arm_notify_die("Oops - undefined instruction", regs,
488 SIGILL, ILL_ILLOPC, pc, 0, 6);
1da177e4 489}
eb0146da 490NOKPROBE_SYMBOL(do_undefinstr)
1da177e4 491
c0e7f7ee
DT
492/*
493 * Handle FIQ similarly to NMI on x86 systems.
494 *
495 * The runtime environment for NMIs is extremely restrictive
496 * (NMIs can pre-empt critical sections meaning almost all locking is
497 * forbidden) meaning this default FIQ handling must only be used in
498 * circumstances where non-maskability improves robustness, such as
499 * watchdog or debug logic.
500 *
501 * This handler is not appropriate for general purpose use in drivers
502 * platform code and can be overrideen using set_fiq_handler.
503 */
504asmlinkage void __exception_irq_entry handle_fiq_as_nmi(struct pt_regs *regs)
505{
506 struct pt_regs *old_regs = set_irq_regs(regs);
507
508 nmi_enter();
509
510 /* nop. FIQ handlers for special arch/arm features can be added here. */
511
512 nmi_exit();
513
514 set_irq_regs(old_regs);
515}
516
1da177e4
LT
517/*
518 * bad_mode handles the impossible case in the vectors. If you see one of
519 * these, then it's extremely serious, and could mean you have buggy hardware.
520 * It never returns, and never tries to sync. We hope that we can at least
521 * dump out some state information...
522 */
ae0a846e 523asmlinkage void bad_mode(struct pt_regs *regs, int reason)
1da177e4
LT
524{
525 console_verbose();
526
4ed89f22 527 pr_crit("Bad mode in %s handler detected\n", handler[reason]);
1da177e4
LT
528
529 die("Oops - bad mode", regs, 0);
530 local_irq_disable();
531 panic("bad mode");
532}
533
534static int bad_syscall(int n, struct pt_regs *regs)
535{
a4980448
RW
536 if ((current->personality & PER_MASK) != PER_LINUX) {
537 send_sig(SIGSEGV, current, 1);
1da177e4
LT
538 return regs->ARM_r0;
539 }
540
541#ifdef CONFIG_DEBUG_USER
542 if (user_debug & UDBG_SYSCALL) {
4ed89f22 543 pr_err("[%d] %s: obsolete system call %08x.\n",
19c5870c 544 task_pid_nr(current), current->comm, n);
e40c2ec6 545 dump_instr(KERN_ERR, regs);
1da177e4
LT
546 }
547#endif
548
05e792e3
EB
549 arm_notify_die("Oops - bad syscall", regs, SIGILL, ILL_ILLTRP,
550 (void __user *)instruction_pointer(regs) -
551 (thumb_mode(regs) ? 2 : 4),
552 n, 0);
1da177e4
LT
553
554 return regs->ARM_r0;
555}
556
c5102f59 557static inline int
28256d61
WD
558__do_cache_op(unsigned long start, unsigned long end)
559{
560 int ret;
28256d61
WD
561
562 do {
b31459ad
JM
563 unsigned long chunk = min(PAGE_SIZE, end - start);
564
3f4aa45c
VM
565 if (fatal_signal_pending(current))
566 return 0;
28256d61
WD
567
568 ret = flush_cache_user_range(start, start + chunk);
569 if (ret)
570 return ret;
571
572 cond_resched();
573 start += chunk;
574 } while (start < end);
575
576 return 0;
577}
578
c5102f59 579static inline int
1da177e4
LT
580do_cache_op(unsigned long start, unsigned long end, int flags)
581{
1da177e4 582 if (end < start || flags)
c5102f59 583 return -EINVAL;
1da177e4 584
96d4f267 585 if (!access_ok(start, end - start))
97c72d89 586 return -EFAULT;
1da177e4 587
28256d61 588 return __do_cache_op(start, end);
1da177e4
LT
589}
590
591/*
592 * Handle all unrecognised system calls.
593 * 0x9f0000 - 0x9fffff are some more esoteric system calls
594 */
595#define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE)
596asmlinkage int arm_syscall(int no, struct pt_regs *regs)
597{
3f2829a3 598 if ((no >> 16) != (__ARM_NR_BASE>> 16))
1da177e4
LT
599 return bad_syscall(no, regs);
600
601 switch (no & 0xffff) {
602 case 0: /* branch through 0 */
05e792e3
EB
603 arm_notify_die("branch through zero", regs,
604 SIGSEGV, SEGV_MAPERR, NULL, 0, 0);
1da177e4
LT
605 return 0;
606
607 case NR(breakpoint): /* SWI BREAK_POINT */
608 regs->ARM_pc -= thumb_mode(regs) ? 2 : 4;
609 ptrace_break(current, regs);
610 return regs->ARM_r0;
611
612 /*
613 * Flush a region from virtual address 'r0' to virtual address 'r1'
614 * _exclusive_. There is no alignment requirement on either address;
615 * user space does not need to know the hardware cache layout.
616 *
617 * r2 contains flags. It should ALWAYS be passed as ZERO until it
618 * is defined to be something else. For now we ignore it, but may
619 * the fires of hell burn in your belly if you break this rule. ;)
620 *
621 * (at a later date, we may want to allow this call to not flush
622 * various aspects of the cache. Passing '0' will guarantee that
623 * everything necessary gets flushed to maintain consistency in
624 * the specified region).
625 */
626 case NR(cacheflush):
c5102f59 627 return do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2);
1da177e4
LT
628
629 case NR(usr26):
630 if (!(elf_hwcap & HWCAP_26BIT))
631 break;
632 regs->ARM_cpsr &= ~MODE32_BIT;
633 return regs->ARM_r0;
634
635 case NR(usr32):
636 if (!(elf_hwcap & HWCAP_26BIT))
637 break;
638 regs->ARM_cpsr |= MODE32_BIT;
639 return regs->ARM_r0;
640
641 case NR(set_tls):
fbfb872f 642 set_tls(regs->ARM_r0);
1da177e4
LT
643 return 0;
644
8fcd6c45
NP
645 case NR(get_tls):
646 return current_thread_info()->tp_value[0];
647
1da177e4
LT
648 default:
649 /* Calls 9f00xx..9f07ff are defined to return -ENOSYS
650 if not implemented, rather than raising SIGILL. This
651 way the calling program can gracefully determine whether
652 a feature is supported. */
bfd2e29f 653 if ((no & 0xffff) <= 0x7ff)
1da177e4
LT
654 return -ENOSYS;
655 break;
656 }
657#ifdef CONFIG_DEBUG_USER
658 /*
659 * experience shows that these seem to indicate that
660 * something catastrophic has happened
661 */
662 if (user_debug & UDBG_SYSCALL) {
4ed89f22 663 pr_err("[%d] %s: arm syscall %d\n",
19c5870c 664 task_pid_nr(current), current->comm, no);
e40c2ec6 665 dump_instr("", regs);
1da177e4 666 if (user_mode(regs)) {
652a12ef 667 __show_regs(regs);
49432d4a 668 c_backtrace(frame_pointer(regs), processor_mode(regs));
1da177e4
LT
669 }
670 }
671#endif
05e792e3
EB
672 arm_notify_die("Oops - bad syscall(2)", regs, SIGILL, ILL_ILLTRP,
673 (void __user *)instruction_pointer(regs) -
674 (thumb_mode(regs) ? 2 : 4),
675 no, 0);
1da177e4
LT
676 return 0;
677}
678
4b0e07a5 679#ifdef CONFIG_TLS_REG_EMUL
2d2669b6
NP
680
681/*
682 * We might be running on an ARMv6+ processor which should have the TLS
4b0e07a5
NP
683 * register but for some reason we can't use it, or maybe an SMP system
684 * using a pre-ARMv6 processor (there are apparently a few prototypes like
685 * that in existence) and therefore access to that register must be
686 * emulated.
2d2669b6
NP
687 */
688
689static int get_tp_trap(struct pt_regs *regs, unsigned int instr)
690{
691 int reg = (instr >> 12) & 15;
692 if (reg == 15)
693 return 1;
a4780ade 694 regs->uregs[reg] = current_thread_info()->tp_value[0];
2d2669b6
NP
695 regs->ARM_pc += 4;
696 return 0;
697}
698
699static struct undef_hook arm_mrc_hook = {
700 .instr_mask = 0x0fff0fff,
701 .instr_val = 0x0e1d0f70,
702 .cpsr_mask = PSR_T_BIT,
703 .cpsr_val = 0,
704 .fn = get_tp_trap,
705};
706
707static int __init arm_mrc_hook_init(void)
708{
709 register_undef_hook(&arm_mrc_hook);
710 return 0;
711}
712
713late_initcall(arm_mrc_hook_init);
714
715#endif
716
1da177e4
LT
717/*
718 * A data abort trap was taken, but we did not handle the instruction.
719 * Try to abort the user program, or panic if it was the kernel.
720 */
721asmlinkage void
722baddataabort(int code, unsigned long instr, struct pt_regs *regs)
723{
724 unsigned long addr = instruction_pointer(regs);
3eb0f519 725
1da177e4
LT
726#ifdef CONFIG_DEBUG_USER
727 if (user_debug & UDBG_BADABORT) {
4ed89f22
RK
728 pr_err("[%d] %s: bad data abort: code %d instr 0x%08lx\n",
729 task_pid_nr(current), current->comm, code, instr);
e40c2ec6 730 dump_instr(KERN_ERR, regs);
1da177e4
LT
731 show_pte(current->mm, addr);
732 }
733#endif
734
05e792e3
EB
735 arm_notify_die("unknown data abort code", regs,
736 SIGILL, ILL_ILLOPC, (void __user *)addr, instr, 0);
1da177e4
LT
737}
738
1da177e4
LT
739void __readwrite_bug(const char *fn)
740{
4ed89f22 741 pr_err("%s called, but not implemented\n", fn);
1da177e4
LT
742 BUG();
743}
744EXPORT_SYMBOL(__readwrite_bug);
745
69529c0e 746void __pte_error(const char *file, int line, pte_t pte)
1da177e4 747{
4ed89f22 748 pr_err("%s:%d: bad pte %08llx.\n", file, line, (long long)pte_val(pte));
1da177e4
LT
749}
750
69529c0e 751void __pmd_error(const char *file, int line, pmd_t pmd)
1da177e4 752{
4ed89f22 753 pr_err("%s:%d: bad pmd %08llx.\n", file, line, (long long)pmd_val(pmd));
1da177e4
LT
754}
755
69529c0e 756void __pgd_error(const char *file, int line, pgd_t pgd)
1da177e4 757{
4ed89f22 758 pr_err("%s:%d: bad pgd %08llx.\n", file, line, (long long)pgd_val(pgd));
1da177e4
LT
759}
760
761asmlinkage void __div0(void)
762{
4ed89f22 763 pr_err("Division by zero in kernel.\n");
1da177e4
LT
764 dump_stack();
765}
766EXPORT_SYMBOL(__div0);
767
768void abort(void)
769{
770 BUG();
771
772 /* if that doesn't kill us, halt */
773 panic("Oops failed to kill thread");
774}
1da177e4
LT
775
776void __init trap_init(void)
5cbad0eb
JW
777{
778 return;
779}
780
f6f91b0d
RK
781#ifdef CONFIG_KUSER_HELPERS
782static void __init kuser_init(void *vectors)
f159f4ed 783{
f6f91b0d
RK
784 extern char __kuser_helper_start[], __kuser_helper_end[];
785 int kuser_sz = __kuser_helper_end - __kuser_helper_start;
786
787 memcpy(vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz);
788
f159f4ed
TL
789 /*
790 * vectors + 0xfe0 = __kuser_get_tls
791 * vectors + 0xfe8 = hardware TLS instruction at 0xffff0fe8
792 */
793 if (tls_emu || has_tls_reg)
f6f91b0d
RK
794 memcpy(vectors + 0xfe0, vectors + 0xfe8, 4);
795}
796#else
5761704a 797static inline void __init kuser_init(void *vectors)
f6f91b0d 798{
f159f4ed 799}
f6f91b0d 800#endif
f159f4ed 801
94e5a85b 802void __init early_trap_init(void *vectors_base)
1da177e4 803{
55bdd694 804#ifndef CONFIG_CPU_V7M
94e5a85b 805 unsigned long vectors = (unsigned long)vectors_base;
7933523d
RK
806 extern char __stubs_start[], __stubs_end[];
807 extern char __vectors_start[], __vectors_end[];
f928d4f2 808 unsigned i;
1da177e4 809
94e5a85b
RK
810 vectors_page = vectors_base;
811
f928d4f2
RK
812 /*
813 * Poison the vectors page with an undefined instruction. This
814 * instruction is chosen to be undefined for both ARM and Thumb
815 * ISAs. The Thumb version is an undefined instruction with a
816 * branch back to the undefined instruction.
817 */
818 for (i = 0; i < PAGE_SIZE / sizeof(u32); i++)
819 ((u32 *)vectors_base)[i] = 0xe7fddef1;
820
7933523d 821 /*
2d2669b6
NP
822 * Copy the vectors, stubs and kuser helpers (in entry-armv.S)
823 * into the vector page, mapped at 0xffff0000, and ensure these
824 * are visible to the instruction stream.
7933523d 825 */
c760fc19 826 memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start);
19accfd3 827 memcpy((void *)vectors + 0x1000, __stubs_start, __stubs_end - __stubs_start);
e00d349e 828
f6f91b0d 829 kuser_init(vectors_base);
f159f4ed 830
19accfd3 831 flush_icache_range(vectors, vectors + PAGE_SIZE * 2);
55bdd694
CM
832#else /* ifndef CONFIG_CPU_V7M */
833 /*
834 * on V7-M there is no need to copy the vector table to a dedicated
835 * memory area. The address is configurable and so a table in the kernel
836 * image can be used.
837 */
838#endif
1da177e4 839}