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1da177e4 LT |
1 | /* |
2 | * linux/arch/arm/kernel/traps.c | |
3 | * | |
4 | * Copyright (C) 1995-2002 Russell King | |
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 LT |
15 | #include <linux/module.h> |
16 | #include <linux/signal.h> | |
17 | #include <linux/spinlock.h> | |
18 | #include <linux/personality.h> | |
19 | #include <linux/ptrace.h> | |
20 | #include <linux/kallsyms.h> | |
31867499 | 21 | #include <linux/delay.h> |
1da177e4 LT |
22 | #include <linux/init.h> |
23 | ||
24 | #include <asm/atomic.h> | |
25 | #include <asm/cacheflush.h> | |
1da177e4 LT |
26 | #include <asm/system.h> |
27 | #include <asm/uaccess.h> | |
28 | #include <asm/unistd.h> | |
29 | #include <asm/traps.h> | |
30 | ||
31 | #include "ptrace.h" | |
e00d349e | 32 | #include "signal.h" |
1da177e4 | 33 | |
1da177e4 LT |
34 | const char *processor_modes[]= |
35 | { "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" , | |
36 | "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26", | |
37 | "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" , | |
38 | "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32" | |
39 | }; | |
40 | ||
41 | static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" }; | |
42 | ||
43 | #ifdef CONFIG_DEBUG_USER | |
44 | unsigned int user_debug; | |
45 | ||
46 | static int __init user_debug_setup(char *str) | |
47 | { | |
48 | get_option(&str, &user_debug); | |
49 | return 1; | |
50 | } | |
51 | __setup("user_debug=", user_debug_setup); | |
52 | #endif | |
53 | ||
54 | void dump_backtrace_entry(unsigned long where, unsigned long from) | |
55 | { | |
56 | #ifdef CONFIG_KALLSYMS | |
57 | printk("[<%08lx>] ", where); | |
58 | print_symbol("(%s) ", where); | |
59 | printk("from [<%08lx>] ", from); | |
60 | print_symbol("(%s)\n", from); | |
61 | #else | |
62 | printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from); | |
63 | #endif | |
64 | } | |
65 | ||
66 | /* | |
67 | * Stack pointers should always be within the kernels view of | |
68 | * physical memory. If it is not there, then we can't dump | |
69 | * out any information relating to the stack. | |
70 | */ | |
71 | static int verify_stack(unsigned long sp) | |
72 | { | |
73 | if (sp < PAGE_OFFSET || (sp > (unsigned long)high_memory && high_memory != 0)) | |
74 | return -EFAULT; | |
75 | ||
76 | return 0; | |
77 | } | |
78 | ||
79 | /* | |
80 | * Dump out the contents of some memory nicely... | |
81 | */ | |
82 | static void dump_mem(const char *str, unsigned long bottom, unsigned long top) | |
83 | { | |
84 | unsigned long p = bottom & ~31; | |
85 | mm_segment_t fs; | |
86 | int i; | |
87 | ||
88 | /* | |
89 | * We need to switch to kernel mode so that we can use __get_user | |
90 | * to safely read from kernel space. Note that we now dump the | |
91 | * code first, just in case the backtrace kills us. | |
92 | */ | |
93 | fs = get_fs(); | |
94 | set_fs(KERNEL_DS); | |
95 | ||
96 | printk("%s(0x%08lx to 0x%08lx)\n", str, bottom, top); | |
97 | ||
98 | for (p = bottom & ~31; p < top;) { | |
99 | printk("%04lx: ", p & 0xffff); | |
100 | ||
101 | for (i = 0; i < 8; i++, p += 4) { | |
102 | unsigned int val; | |
103 | ||
104 | if (p < bottom || p >= top) | |
105 | printk(" "); | |
106 | else { | |
107 | __get_user(val, (unsigned long *)p); | |
108 | printk("%08x ", val); | |
109 | } | |
110 | } | |
111 | printk ("\n"); | |
112 | } | |
113 | ||
114 | set_fs(fs); | |
115 | } | |
116 | ||
117 | static void dump_instr(struct pt_regs *regs) | |
118 | { | |
119 | unsigned long addr = instruction_pointer(regs); | |
120 | const int thumb = thumb_mode(regs); | |
121 | const int width = thumb ? 4 : 8; | |
122 | mm_segment_t fs; | |
123 | int i; | |
124 | ||
125 | /* | |
126 | * We need to switch to kernel mode so that we can use __get_user | |
127 | * to safely read from kernel space. Note that we now dump the | |
128 | * code first, just in case the backtrace kills us. | |
129 | */ | |
130 | fs = get_fs(); | |
131 | set_fs(KERNEL_DS); | |
132 | ||
133 | printk("Code: "); | |
134 | for (i = -4; i < 1; i++) { | |
135 | unsigned int val, bad; | |
136 | ||
137 | if (thumb) | |
138 | bad = __get_user(val, &((u16 *)addr)[i]); | |
139 | else | |
140 | bad = __get_user(val, &((u32 *)addr)[i]); | |
141 | ||
142 | if (!bad) | |
143 | printk(i == 0 ? "(%0*x) " : "%0*x ", width, val); | |
144 | else { | |
145 | printk("bad PC value."); | |
146 | break; | |
147 | } | |
148 | } | |
149 | printk("\n"); | |
150 | ||
151 | set_fs(fs); | |
152 | } | |
153 | ||
154 | static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) | |
155 | { | |
156 | unsigned int fp; | |
157 | int ok = 1; | |
158 | ||
159 | printk("Backtrace: "); | |
160 | fp = regs->ARM_fp; | |
161 | if (!fp) { | |
162 | printk("no frame pointer"); | |
163 | ok = 0; | |
164 | } else if (verify_stack(fp)) { | |
165 | printk("invalid frame pointer 0x%08x", fp); | |
166 | ok = 0; | |
55205823 | 167 | } else if (fp < (unsigned long)end_of_stack(tsk)) |
1da177e4 LT |
168 | printk("frame pointer underflow"); |
169 | printk("\n"); | |
170 | ||
171 | if (ok) | |
172 | c_backtrace(fp, processor_mode(regs)); | |
173 | } | |
174 | ||
175 | void dump_stack(void) | |
176 | { | |
177 | #ifdef CONFIG_DEBUG_ERRORS | |
178 | __backtrace(); | |
179 | #endif | |
180 | } | |
181 | ||
182 | EXPORT_SYMBOL(dump_stack); | |
183 | ||
184 | void show_stack(struct task_struct *tsk, unsigned long *sp) | |
185 | { | |
186 | unsigned long fp; | |
187 | ||
188 | if (!tsk) | |
189 | tsk = current; | |
190 | ||
191 | if (tsk != current) | |
192 | fp = thread_saved_fp(tsk); | |
193 | else | |
194 | asm("mov%? %0, fp" : "=r" (fp)); | |
195 | ||
196 | c_backtrace(fp, 0x10); | |
197 | barrier(); | |
198 | } | |
199 | ||
d362979a | 200 | static void __die(const char *str, int err, struct thread_info *thread, struct pt_regs *regs) |
1da177e4 | 201 | { |
d362979a | 202 | struct task_struct *tsk = thread->task; |
1da177e4 LT |
203 | static int die_counter; |
204 | ||
1da177e4 LT |
205 | printk("Internal error: %s: %x [#%d]\n", str, err, ++die_counter); |
206 | print_modules(); | |
652a12ef | 207 | __show_regs(regs); |
1da177e4 | 208 | printk("Process %s (pid: %d, stack limit = 0x%p)\n", |
d362979a | 209 | tsk->comm, tsk->pid, thread + 1); |
1da177e4 LT |
210 | |
211 | if (!user_mode(regs) || in_interrupt()) { | |
4f7a1812 | 212 | dump_mem("Stack: ", regs->ARM_sp, |
32d39a93 | 213 | THREAD_SIZE + (unsigned long)task_stack_page(tsk)); |
1da177e4 LT |
214 | dump_backtrace(regs, tsk); |
215 | dump_instr(regs); | |
216 | } | |
d362979a | 217 | } |
1da177e4 | 218 | |
d362979a RK |
219 | DEFINE_SPINLOCK(die_lock); |
220 | ||
221 | /* | |
222 | * This function is protected against re-entrancy. | |
223 | */ | |
224 | NORET_TYPE void die(const char *str, struct pt_regs *regs, int err) | |
225 | { | |
226 | struct thread_info *thread = current_thread_info(); | |
227 | ||
228 | console_verbose(); | |
229 | spin_lock_irq(&die_lock); | |
230 | bust_spinlocks(1); | |
231 | __die(str, err, thread, regs); | |
1da177e4 LT |
232 | bust_spinlocks(0); |
233 | spin_unlock_irq(&die_lock); | |
31867499 RK |
234 | |
235 | if (panic_on_oops) { | |
236 | printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n"); | |
237 | ssleep(5); | |
238 | panic("Fatal exception"); | |
239 | } | |
240 | ||
1da177e4 LT |
241 | do_exit(SIGSEGV); |
242 | } | |
243 | ||
cfb0810e RK |
244 | void notify_die(const char *str, struct pt_regs *regs, struct siginfo *info, |
245 | unsigned long err, unsigned long trap) | |
1da177e4 LT |
246 | { |
247 | if (user_mode(regs)) { | |
248 | current->thread.error_code = err; | |
249 | current->thread.trap_no = trap; | |
250 | ||
251 | force_sig_info(info->si_signo, info, current); | |
252 | } else { | |
253 | die(str, regs, err); | |
254 | } | |
255 | } | |
256 | ||
257 | static LIST_HEAD(undef_hook); | |
258 | static DEFINE_SPINLOCK(undef_lock); | |
259 | ||
260 | void register_undef_hook(struct undef_hook *hook) | |
261 | { | |
109d89ca RK |
262 | unsigned long flags; |
263 | ||
264 | spin_lock_irqsave(&undef_lock, flags); | |
1da177e4 | 265 | list_add(&hook->node, &undef_hook); |
109d89ca | 266 | spin_unlock_irqrestore(&undef_lock, flags); |
1da177e4 LT |
267 | } |
268 | ||
269 | void unregister_undef_hook(struct undef_hook *hook) | |
270 | { | |
109d89ca RK |
271 | unsigned long flags; |
272 | ||
273 | spin_lock_irqsave(&undef_lock, flags); | |
1da177e4 | 274 | list_del(&hook->node); |
109d89ca | 275 | spin_unlock_irqrestore(&undef_lock, flags); |
1da177e4 LT |
276 | } |
277 | ||
278 | asmlinkage void do_undefinstr(struct pt_regs *regs) | |
279 | { | |
280 | unsigned int correction = thumb_mode(regs) ? 2 : 4; | |
281 | unsigned int instr; | |
282 | struct undef_hook *hook; | |
283 | siginfo_t info; | |
284 | void __user *pc; | |
285 | ||
286 | /* | |
287 | * According to the ARM ARM, PC is 2 or 4 bytes ahead, | |
288 | * depending whether we're in Thumb mode or not. | |
289 | * Correct this offset. | |
290 | */ | |
291 | regs->ARM_pc -= correction; | |
292 | ||
293 | pc = (void __user *)instruction_pointer(regs); | |
294 | if (thumb_mode(regs)) { | |
295 | get_user(instr, (u16 __user *)pc); | |
296 | } else { | |
297 | get_user(instr, (u32 __user *)pc); | |
298 | } | |
299 | ||
300 | spin_lock_irq(&undef_lock); | |
301 | list_for_each_entry(hook, &undef_hook, node) { | |
302 | if ((instr & hook->instr_mask) == hook->instr_val && | |
303 | (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val) { | |
304 | if (hook->fn(regs, instr) == 0) { | |
305 | spin_unlock_irq(&undef_lock); | |
306 | return; | |
307 | } | |
308 | } | |
309 | } | |
310 | spin_unlock_irq(&undef_lock); | |
311 | ||
312 | #ifdef CONFIG_DEBUG_USER | |
313 | if (user_debug & UDBG_UNDEFINED) { | |
314 | printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n", | |
315 | current->comm, current->pid, pc); | |
316 | dump_instr(regs); | |
317 | } | |
318 | #endif | |
319 | ||
320 | info.si_signo = SIGILL; | |
321 | info.si_errno = 0; | |
322 | info.si_code = ILL_ILLOPC; | |
323 | info.si_addr = pc; | |
324 | ||
325 | notify_die("Oops - undefined instruction", regs, &info, 0, 6); | |
326 | } | |
327 | ||
328 | asmlinkage void do_unexp_fiq (struct pt_regs *regs) | |
329 | { | |
330 | #ifndef CONFIG_IGNORE_FIQ | |
331 | printk("Hmm. Unexpected FIQ received, but trying to continue\n"); | |
332 | printk("You may have a hardware problem...\n"); | |
333 | #endif | |
334 | } | |
335 | ||
336 | /* | |
337 | * bad_mode handles the impossible case in the vectors. If you see one of | |
338 | * these, then it's extremely serious, and could mean you have buggy hardware. | |
339 | * It never returns, and never tries to sync. We hope that we can at least | |
340 | * dump out some state information... | |
341 | */ | |
342 | asmlinkage void bad_mode(struct pt_regs *regs, int reason, int proc_mode) | |
343 | { | |
344 | console_verbose(); | |
345 | ||
346 | printk(KERN_CRIT "Bad mode in %s handler detected: mode %s\n", | |
347 | handler[reason], processor_modes[proc_mode]); | |
348 | ||
349 | die("Oops - bad mode", regs, 0); | |
350 | local_irq_disable(); | |
351 | panic("bad mode"); | |
352 | } | |
353 | ||
354 | static int bad_syscall(int n, struct pt_regs *regs) | |
355 | { | |
356 | struct thread_info *thread = current_thread_info(); | |
357 | siginfo_t info; | |
358 | ||
a999cb04 NP |
359 | if (current->personality != PER_LINUX && |
360 | current->personality != PER_LINUX_32BIT && | |
361 | thread->exec_domain->handler) { | |
1da177e4 LT |
362 | thread->exec_domain->handler(n, regs); |
363 | return regs->ARM_r0; | |
364 | } | |
365 | ||
366 | #ifdef CONFIG_DEBUG_USER | |
367 | if (user_debug & UDBG_SYSCALL) { | |
368 | printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n", | |
369 | current->pid, current->comm, n); | |
370 | dump_instr(regs); | |
371 | } | |
372 | #endif | |
373 | ||
374 | info.si_signo = SIGILL; | |
375 | info.si_errno = 0; | |
376 | info.si_code = ILL_ILLTRP; | |
377 | info.si_addr = (void __user *)instruction_pointer(regs) - | |
378 | (thumb_mode(regs) ? 2 : 4); | |
379 | ||
380 | notify_die("Oops - bad syscall", regs, &info, n, 0); | |
381 | ||
382 | return regs->ARM_r0; | |
383 | } | |
384 | ||
385 | static inline void | |
386 | do_cache_op(unsigned long start, unsigned long end, int flags) | |
387 | { | |
388 | struct vm_area_struct *vma; | |
389 | ||
390 | if (end < start || flags) | |
391 | return; | |
392 | ||
393 | vma = find_vma(current->active_mm, start); | |
394 | if (vma && vma->vm_start < end) { | |
395 | if (start < vma->vm_start) | |
396 | start = vma->vm_start; | |
397 | if (end > vma->vm_end) | |
398 | end = vma->vm_end; | |
399 | ||
400 | flush_cache_user_range(vma, start, end); | |
401 | } | |
402 | } | |
403 | ||
404 | /* | |
405 | * Handle all unrecognised system calls. | |
406 | * 0x9f0000 - 0x9fffff are some more esoteric system calls | |
407 | */ | |
408 | #define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE) | |
409 | asmlinkage int arm_syscall(int no, struct pt_regs *regs) | |
410 | { | |
411 | struct thread_info *thread = current_thread_info(); | |
412 | siginfo_t info; | |
413 | ||
3f2829a3 | 414 | if ((no >> 16) != (__ARM_NR_BASE>> 16)) |
1da177e4 LT |
415 | return bad_syscall(no, regs); |
416 | ||
417 | switch (no & 0xffff) { | |
418 | case 0: /* branch through 0 */ | |
419 | info.si_signo = SIGSEGV; | |
420 | info.si_errno = 0; | |
421 | info.si_code = SEGV_MAPERR; | |
422 | info.si_addr = NULL; | |
423 | ||
424 | notify_die("branch through zero", regs, &info, 0, 0); | |
425 | return 0; | |
426 | ||
427 | case NR(breakpoint): /* SWI BREAK_POINT */ | |
428 | regs->ARM_pc -= thumb_mode(regs) ? 2 : 4; | |
429 | ptrace_break(current, regs); | |
430 | return regs->ARM_r0; | |
431 | ||
432 | /* | |
433 | * Flush a region from virtual address 'r0' to virtual address 'r1' | |
434 | * _exclusive_. There is no alignment requirement on either address; | |
435 | * user space does not need to know the hardware cache layout. | |
436 | * | |
437 | * r2 contains flags. It should ALWAYS be passed as ZERO until it | |
438 | * is defined to be something else. For now we ignore it, but may | |
439 | * the fires of hell burn in your belly if you break this rule. ;) | |
440 | * | |
441 | * (at a later date, we may want to allow this call to not flush | |
442 | * various aspects of the cache. Passing '0' will guarantee that | |
443 | * everything necessary gets flushed to maintain consistency in | |
444 | * the specified region). | |
445 | */ | |
446 | case NR(cacheflush): | |
447 | do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2); | |
448 | return 0; | |
449 | ||
450 | case NR(usr26): | |
451 | if (!(elf_hwcap & HWCAP_26BIT)) | |
452 | break; | |
453 | regs->ARM_cpsr &= ~MODE32_BIT; | |
454 | return regs->ARM_r0; | |
455 | ||
456 | case NR(usr32): | |
457 | if (!(elf_hwcap & HWCAP_26BIT)) | |
458 | break; | |
459 | regs->ARM_cpsr |= MODE32_BIT; | |
460 | return regs->ARM_r0; | |
461 | ||
462 | case NR(set_tls): | |
463 | thread->tp_value = regs->ARM_r0; | |
4b0e07a5 | 464 | #if defined(CONFIG_HAS_TLS_REG) |
2d2669b6 | 465 | asm ("mcr p15, 0, %0, c13, c0, 3" : : "r" (regs->ARM_r0) ); |
4b0e07a5 | 466 | #elif !defined(CONFIG_TLS_REG_EMUL) |
1da177e4 | 467 | /* |
2d2669b6 NP |
468 | * User space must never try to access this directly. |
469 | * Expect your app to break eventually if you do so. | |
470 | * The user helper at 0xffff0fe0 must be used instead. | |
471 | * (see entry-armv.S for details) | |
1da177e4 | 472 | */ |
2d2669b6 NP |
473 | *((unsigned int *)0xffff0ff0) = regs->ARM_r0; |
474 | #endif | |
1da177e4 LT |
475 | return 0; |
476 | ||
dcef1f63 NP |
477 | #ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG |
478 | /* | |
479 | * Atomically store r1 in *r2 if *r2 is equal to r0 for user space. | |
480 | * Return zero in r0 if *MEM was changed or non-zero if no exchange | |
481 | * happened. Also set the user C flag accordingly. | |
482 | * If access permissions have to be fixed up then non-zero is | |
483 | * returned and the operation has to be re-attempted. | |
484 | * | |
485 | * *NOTE*: This is a ghost syscall private to the kernel. Only the | |
486 | * __kuser_cmpxchg code in entry-armv.S should be aware of its | |
487 | * existence. Don't ever use this from user code. | |
488 | */ | |
489 | case 0xfff0: | |
490 | { | |
491 | extern void do_DataAbort(unsigned long addr, unsigned int fsr, | |
492 | struct pt_regs *regs); | |
493 | unsigned long val; | |
494 | unsigned long addr = regs->ARM_r2; | |
495 | struct mm_struct *mm = current->mm; | |
496 | pgd_t *pgd; pmd_t *pmd; pte_t *pte; | |
69b04754 | 497 | spinlock_t *ptl; |
dcef1f63 NP |
498 | |
499 | regs->ARM_cpsr &= ~PSR_C_BIT; | |
69b04754 | 500 | down_read(&mm->mmap_sem); |
dcef1f63 NP |
501 | pgd = pgd_offset(mm, addr); |
502 | if (!pgd_present(*pgd)) | |
503 | goto bad_access; | |
504 | pmd = pmd_offset(pgd, addr); | |
505 | if (!pmd_present(*pmd)) | |
506 | goto bad_access; | |
69b04754 | 507 | pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
2ce9804f | 508 | if (!pte_present(*pte) || !pte_dirty(*pte)) { |
69b04754 | 509 | pte_unmap_unlock(pte, ptl); |
dcef1f63 | 510 | goto bad_access; |
69b04754 | 511 | } |
dcef1f63 NP |
512 | val = *(unsigned long *)addr; |
513 | val -= regs->ARM_r0; | |
514 | if (val == 0) { | |
515 | *(unsigned long *)addr = regs->ARM_r1; | |
516 | regs->ARM_cpsr |= PSR_C_BIT; | |
517 | } | |
69b04754 HD |
518 | pte_unmap_unlock(pte, ptl); |
519 | up_read(&mm->mmap_sem); | |
dcef1f63 NP |
520 | return val; |
521 | ||
522 | bad_access: | |
69b04754 | 523 | up_read(&mm->mmap_sem); |
74f88494 | 524 | /* simulate a write access fault */ |
dcef1f63 NP |
525 | do_DataAbort(addr, 15 + (1 << 11), regs); |
526 | return -1; | |
527 | } | |
528 | #endif | |
529 | ||
1da177e4 LT |
530 | default: |
531 | /* Calls 9f00xx..9f07ff are defined to return -ENOSYS | |
532 | if not implemented, rather than raising SIGILL. This | |
533 | way the calling program can gracefully determine whether | |
534 | a feature is supported. */ | |
535 | if (no <= 0x7ff) | |
536 | return -ENOSYS; | |
537 | break; | |
538 | } | |
539 | #ifdef CONFIG_DEBUG_USER | |
540 | /* | |
541 | * experience shows that these seem to indicate that | |
542 | * something catastrophic has happened | |
543 | */ | |
544 | if (user_debug & UDBG_SYSCALL) { | |
545 | printk("[%d] %s: arm syscall %d\n", | |
546 | current->pid, current->comm, no); | |
547 | dump_instr(regs); | |
548 | if (user_mode(regs)) { | |
652a12ef | 549 | __show_regs(regs); |
1da177e4 LT |
550 | c_backtrace(regs->ARM_fp, processor_mode(regs)); |
551 | } | |
552 | } | |
553 | #endif | |
554 | info.si_signo = SIGILL; | |
555 | info.si_errno = 0; | |
556 | info.si_code = ILL_ILLTRP; | |
557 | info.si_addr = (void __user *)instruction_pointer(regs) - | |
558 | (thumb_mode(regs) ? 2 : 4); | |
559 | ||
560 | notify_die("Oops - bad syscall(2)", regs, &info, no, 0); | |
561 | return 0; | |
562 | } | |
563 | ||
4b0e07a5 | 564 | #ifdef CONFIG_TLS_REG_EMUL |
2d2669b6 NP |
565 | |
566 | /* | |
567 | * We might be running on an ARMv6+ processor which should have the TLS | |
4b0e07a5 NP |
568 | * register but for some reason we can't use it, or maybe an SMP system |
569 | * using a pre-ARMv6 processor (there are apparently a few prototypes like | |
570 | * that in existence) and therefore access to that register must be | |
571 | * emulated. | |
2d2669b6 NP |
572 | */ |
573 | ||
574 | static int get_tp_trap(struct pt_regs *regs, unsigned int instr) | |
575 | { | |
576 | int reg = (instr >> 12) & 15; | |
577 | if (reg == 15) | |
578 | return 1; | |
579 | regs->uregs[reg] = current_thread_info()->tp_value; | |
580 | regs->ARM_pc += 4; | |
581 | return 0; | |
582 | } | |
583 | ||
584 | static struct undef_hook arm_mrc_hook = { | |
585 | .instr_mask = 0x0fff0fff, | |
586 | .instr_val = 0x0e1d0f70, | |
587 | .cpsr_mask = PSR_T_BIT, | |
588 | .cpsr_val = 0, | |
589 | .fn = get_tp_trap, | |
590 | }; | |
591 | ||
592 | static int __init arm_mrc_hook_init(void) | |
593 | { | |
594 | register_undef_hook(&arm_mrc_hook); | |
595 | return 0; | |
596 | } | |
597 | ||
598 | late_initcall(arm_mrc_hook_init); | |
599 | ||
600 | #endif | |
601 | ||
1da177e4 LT |
602 | void __bad_xchg(volatile void *ptr, int size) |
603 | { | |
604 | printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n", | |
605 | __builtin_return_address(0), ptr, size); | |
606 | BUG(); | |
607 | } | |
608 | EXPORT_SYMBOL(__bad_xchg); | |
609 | ||
610 | /* | |
611 | * A data abort trap was taken, but we did not handle the instruction. | |
612 | * Try to abort the user program, or panic if it was the kernel. | |
613 | */ | |
614 | asmlinkage void | |
615 | baddataabort(int code, unsigned long instr, struct pt_regs *regs) | |
616 | { | |
617 | unsigned long addr = instruction_pointer(regs); | |
618 | siginfo_t info; | |
619 | ||
620 | #ifdef CONFIG_DEBUG_USER | |
621 | if (user_debug & UDBG_BADABORT) { | |
622 | printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n", | |
623 | current->pid, current->comm, code, instr); | |
624 | dump_instr(regs); | |
625 | show_pte(current->mm, addr); | |
626 | } | |
627 | #endif | |
628 | ||
629 | info.si_signo = SIGILL; | |
630 | info.si_errno = 0; | |
631 | info.si_code = ILL_ILLOPC; | |
632 | info.si_addr = (void __user *)addr; | |
633 | ||
634 | notify_die("unknown data abort code", regs, &info, instr, 0); | |
635 | } | |
636 | ||
33215652 | 637 | void __attribute__((noreturn)) __bug(const char *file, int line, void *data) |
1da177e4 LT |
638 | { |
639 | printk(KERN_CRIT"kernel BUG at %s:%d!", file, line); | |
640 | if (data) | |
641 | printk(" - extra data = %p", data); | |
642 | printk("\n"); | |
643 | *(int *)0 = 0; | |
6a1ced59 CM |
644 | |
645 | /* Avoid "noreturn function does return" */ | |
646 | for (;;); | |
1da177e4 LT |
647 | } |
648 | EXPORT_SYMBOL(__bug); | |
649 | ||
650 | void __readwrite_bug(const char *fn) | |
651 | { | |
652 | printk("%s called, but not implemented\n", fn); | |
653 | BUG(); | |
654 | } | |
655 | EXPORT_SYMBOL(__readwrite_bug); | |
656 | ||
657 | void __pte_error(const char *file, int line, unsigned long val) | |
658 | { | |
659 | printk("%s:%d: bad pte %08lx.\n", file, line, val); | |
660 | } | |
661 | ||
662 | void __pmd_error(const char *file, int line, unsigned long val) | |
663 | { | |
664 | printk("%s:%d: bad pmd %08lx.\n", file, line, val); | |
665 | } | |
666 | ||
667 | void __pgd_error(const char *file, int line, unsigned long val) | |
668 | { | |
669 | printk("%s:%d: bad pgd %08lx.\n", file, line, val); | |
670 | } | |
671 | ||
672 | asmlinkage void __div0(void) | |
673 | { | |
674 | printk("Division by zero in kernel.\n"); | |
675 | dump_stack(); | |
676 | } | |
677 | EXPORT_SYMBOL(__div0); | |
678 | ||
679 | void abort(void) | |
680 | { | |
681 | BUG(); | |
682 | ||
683 | /* if that doesn't kill us, halt */ | |
684 | panic("Oops failed to kill thread"); | |
685 | } | |
686 | EXPORT_SYMBOL(abort); | |
687 | ||
688 | void __init trap_init(void) | |
689 | { | |
c760fc19 | 690 | unsigned long vectors = CONFIG_VECTORS_BASE; |
7933523d RK |
691 | extern char __stubs_start[], __stubs_end[]; |
692 | extern char __vectors_start[], __vectors_end[]; | |
2d2669b6 NP |
693 | extern char __kuser_helper_start[], __kuser_helper_end[]; |
694 | int kuser_sz = __kuser_helper_end - __kuser_helper_start; | |
1da177e4 | 695 | |
7933523d | 696 | /* |
2d2669b6 NP |
697 | * Copy the vectors, stubs and kuser helpers (in entry-armv.S) |
698 | * into the vector page, mapped at 0xffff0000, and ensure these | |
699 | * are visible to the instruction stream. | |
7933523d | 700 | */ |
c760fc19 HC |
701 | memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start); |
702 | memcpy((void *)vectors + 0x200, __stubs_start, __stubs_end - __stubs_start); | |
703 | memcpy((void *)vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz); | |
e00d349e RK |
704 | |
705 | /* | |
706 | * Copy signal return handlers into the vector page, and | |
707 | * set sigreturn to be a pointer to these. | |
708 | */ | |
709 | memcpy((void *)KERN_SIGRETURN_CODE, sigreturn_codes, | |
710 | sizeof(sigreturn_codes)); | |
711 | ||
c760fc19 | 712 | flush_icache_range(vectors, vectors + PAGE_SIZE); |
1da177e4 LT |
713 | modify_domain(DOMAIN_USER, DOMAIN_CLIENT); |
714 | } |