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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> | |
1da177e4 | 19 | #include <linux/kallsyms.h> |
31867499 | 20 | #include <linux/delay.h> |
1da177e4 LT |
21 | #include <linux/init.h> |
22 | ||
23 | #include <asm/atomic.h> | |
24 | #include <asm/cacheflush.h> | |
1da177e4 LT |
25 | #include <asm/system.h> |
26 | #include <asm/uaccess.h> | |
27 | #include <asm/unistd.h> | |
28 | #include <asm/traps.h> | |
9ca3f07b | 29 | #include <asm/io.h> |
1da177e4 LT |
30 | |
31 | #include "ptrace.h" | |
e00d349e | 32 | #include "signal.h" |
1da177e4 | 33 | |
1da177e4 LT |
34 | static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" }; |
35 | ||
36 | #ifdef CONFIG_DEBUG_USER | |
37 | unsigned int user_debug; | |
38 | ||
39 | static int __init user_debug_setup(char *str) | |
40 | { | |
41 | get_option(&str, &user_debug); | |
42 | return 1; | |
43 | } | |
44 | __setup("user_debug=", user_debug_setup); | |
45 | #endif | |
46 | ||
7ab3f8d5 RK |
47 | static void dump_mem(const char *str, unsigned long bottom, unsigned long top); |
48 | ||
49 | static inline int in_exception_text(unsigned long ptr) | |
50 | { | |
51 | extern char __exception_text_start[]; | |
52 | extern char __exception_text_end[]; | |
53 | ||
54 | return ptr >= (unsigned long)&__exception_text_start && | |
55 | ptr < (unsigned long)&__exception_text_end; | |
56 | } | |
57 | ||
58 | void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame) | |
1da177e4 LT |
59 | { |
60 | #ifdef CONFIG_KALLSYMS | |
61 | printk("[<%08lx>] ", where); | |
62 | print_symbol("(%s) ", where); | |
63 | printk("from [<%08lx>] ", from); | |
64 | print_symbol("(%s)\n", from); | |
65 | #else | |
66 | printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from); | |
67 | #endif | |
7ab3f8d5 RK |
68 | |
69 | if (in_exception_text(where)) | |
70 | dump_mem("Exception stack", frame + 4, frame + 4 + sizeof(struct pt_regs)); | |
1da177e4 LT |
71 | } |
72 | ||
73 | /* | |
74 | * Stack pointers should always be within the kernels view of | |
75 | * physical memory. If it is not there, then we can't dump | |
76 | * out any information relating to the stack. | |
77 | */ | |
78 | static int verify_stack(unsigned long sp) | |
79 | { | |
80 | if (sp < PAGE_OFFSET || (sp > (unsigned long)high_memory && high_memory != 0)) | |
81 | return -EFAULT; | |
82 | ||
83 | return 0; | |
84 | } | |
85 | ||
86 | /* | |
87 | * Dump out the contents of some memory nicely... | |
88 | */ | |
89 | static void dump_mem(const char *str, unsigned long bottom, unsigned long top) | |
90 | { | |
91 | unsigned long p = bottom & ~31; | |
92 | mm_segment_t fs; | |
93 | int i; | |
94 | ||
95 | /* | |
96 | * We need to switch to kernel mode so that we can use __get_user | |
97 | * to safely read from kernel space. Note that we now dump the | |
98 | * code first, just in case the backtrace kills us. | |
99 | */ | |
100 | fs = get_fs(); | |
101 | set_fs(KERNEL_DS); | |
102 | ||
103 | printk("%s(0x%08lx to 0x%08lx)\n", str, bottom, top); | |
104 | ||
105 | for (p = bottom & ~31; p < top;) { | |
106 | printk("%04lx: ", p & 0xffff); | |
107 | ||
108 | for (i = 0; i < 8; i++, p += 4) { | |
109 | unsigned int val; | |
110 | ||
111 | if (p < bottom || p >= top) | |
112 | printk(" "); | |
113 | else { | |
114 | __get_user(val, (unsigned long *)p); | |
115 | printk("%08x ", val); | |
116 | } | |
117 | } | |
118 | printk ("\n"); | |
119 | } | |
120 | ||
121 | set_fs(fs); | |
122 | } | |
123 | ||
124 | static void dump_instr(struct pt_regs *regs) | |
125 | { | |
126 | unsigned long addr = instruction_pointer(regs); | |
127 | const int thumb = thumb_mode(regs); | |
128 | const int width = thumb ? 4 : 8; | |
129 | mm_segment_t fs; | |
130 | int i; | |
131 | ||
132 | /* | |
133 | * We need to switch to kernel mode so that we can use __get_user | |
134 | * to safely read from kernel space. Note that we now dump the | |
135 | * code first, just in case the backtrace kills us. | |
136 | */ | |
137 | fs = get_fs(); | |
138 | set_fs(KERNEL_DS); | |
139 | ||
140 | printk("Code: "); | |
141 | for (i = -4; i < 1; i++) { | |
142 | unsigned int val, bad; | |
143 | ||
144 | if (thumb) | |
145 | bad = __get_user(val, &((u16 *)addr)[i]); | |
146 | else | |
147 | bad = __get_user(val, &((u32 *)addr)[i]); | |
148 | ||
149 | if (!bad) | |
150 | printk(i == 0 ? "(%0*x) " : "%0*x ", width, val); | |
151 | else { | |
152 | printk("bad PC value."); | |
153 | break; | |
154 | } | |
155 | } | |
156 | printk("\n"); | |
157 | ||
158 | set_fs(fs); | |
159 | } | |
160 | ||
161 | static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) | |
162 | { | |
163 | unsigned int fp; | |
164 | int ok = 1; | |
165 | ||
166 | printk("Backtrace: "); | |
167 | fp = regs->ARM_fp; | |
168 | if (!fp) { | |
169 | printk("no frame pointer"); | |
170 | ok = 0; | |
171 | } else if (verify_stack(fp)) { | |
172 | printk("invalid frame pointer 0x%08x", fp); | |
173 | ok = 0; | |
55205823 | 174 | } else if (fp < (unsigned long)end_of_stack(tsk)) |
1da177e4 LT |
175 | printk("frame pointer underflow"); |
176 | printk("\n"); | |
177 | ||
178 | if (ok) | |
179 | c_backtrace(fp, processor_mode(regs)); | |
180 | } | |
181 | ||
182 | void dump_stack(void) | |
183 | { | |
1da177e4 | 184 | __backtrace(); |
1da177e4 LT |
185 | } |
186 | ||
187 | EXPORT_SYMBOL(dump_stack); | |
188 | ||
189 | void show_stack(struct task_struct *tsk, unsigned long *sp) | |
190 | { | |
191 | unsigned long fp; | |
192 | ||
193 | if (!tsk) | |
194 | tsk = current; | |
195 | ||
196 | if (tsk != current) | |
197 | fp = thread_saved_fp(tsk); | |
198 | else | |
6a39dd62 | 199 | asm("mov %0, fp" : "=r" (fp) : : "cc"); |
1da177e4 LT |
200 | |
201 | c_backtrace(fp, 0x10); | |
202 | barrier(); | |
203 | } | |
204 | ||
d9202429 RK |
205 | #ifdef CONFIG_PREEMPT |
206 | #define S_PREEMPT " PREEMPT" | |
207 | #else | |
208 | #define S_PREEMPT "" | |
209 | #endif | |
210 | #ifdef CONFIG_SMP | |
211 | #define S_SMP " SMP" | |
212 | #else | |
213 | #define S_SMP "" | |
214 | #endif | |
215 | ||
d362979a | 216 | static void __die(const char *str, int err, struct thread_info *thread, struct pt_regs *regs) |
1da177e4 | 217 | { |
d362979a | 218 | struct task_struct *tsk = thread->task; |
1da177e4 LT |
219 | static int die_counter; |
220 | ||
d9202429 RK |
221 | printk("Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n", |
222 | str, err, ++die_counter); | |
1da177e4 | 223 | print_modules(); |
652a12ef | 224 | __show_regs(regs); |
1da177e4 | 225 | printk("Process %s (pid: %d, stack limit = 0x%p)\n", |
19c5870c | 226 | tsk->comm, task_pid_nr(tsk), thread + 1); |
1da177e4 LT |
227 | |
228 | if (!user_mode(regs) || in_interrupt()) { | |
4f7a1812 | 229 | dump_mem("Stack: ", regs->ARM_sp, |
32d39a93 | 230 | THREAD_SIZE + (unsigned long)task_stack_page(tsk)); |
1da177e4 LT |
231 | dump_backtrace(regs, tsk); |
232 | dump_instr(regs); | |
233 | } | |
d362979a | 234 | } |
1da177e4 | 235 | |
d362979a RK |
236 | DEFINE_SPINLOCK(die_lock); |
237 | ||
238 | /* | |
239 | * This function is protected against re-entrancy. | |
240 | */ | |
241 | NORET_TYPE void die(const char *str, struct pt_regs *regs, int err) | |
242 | { | |
243 | struct thread_info *thread = current_thread_info(); | |
244 | ||
d9202429 RK |
245 | oops_enter(); |
246 | ||
d362979a RK |
247 | console_verbose(); |
248 | spin_lock_irq(&die_lock); | |
249 | bust_spinlocks(1); | |
250 | __die(str, err, thread, regs); | |
1da177e4 | 251 | bust_spinlocks(0); |
bcdcd8e7 | 252 | add_taint(TAINT_DIE); |
1da177e4 | 253 | spin_unlock_irq(&die_lock); |
31867499 | 254 | |
d9202429 RK |
255 | if (in_interrupt()) |
256 | panic("Fatal exception in interrupt"); | |
257 | ||
cea6a4ba | 258 | if (panic_on_oops) |
012c437d | 259 | panic("Fatal exception"); |
31867499 | 260 | |
d9202429 | 261 | oops_exit(); |
1da177e4 LT |
262 | do_exit(SIGSEGV); |
263 | } | |
264 | ||
1eeb66a1 CH |
265 | void arm_notify_die(const char *str, struct pt_regs *regs, |
266 | struct siginfo *info, unsigned long err, unsigned long trap) | |
1da177e4 LT |
267 | { |
268 | if (user_mode(regs)) { | |
269 | current->thread.error_code = err; | |
270 | current->thread.trap_no = trap; | |
271 | ||
272 | force_sig_info(info->si_signo, info, current); | |
273 | } else { | |
274 | die(str, regs, err); | |
275 | } | |
276 | } | |
277 | ||
278 | static LIST_HEAD(undef_hook); | |
279 | static DEFINE_SPINLOCK(undef_lock); | |
280 | ||
281 | void register_undef_hook(struct undef_hook *hook) | |
282 | { | |
109d89ca RK |
283 | unsigned long flags; |
284 | ||
285 | spin_lock_irqsave(&undef_lock, flags); | |
1da177e4 | 286 | list_add(&hook->node, &undef_hook); |
109d89ca | 287 | spin_unlock_irqrestore(&undef_lock, flags); |
1da177e4 LT |
288 | } |
289 | ||
290 | void unregister_undef_hook(struct undef_hook *hook) | |
291 | { | |
109d89ca RK |
292 | unsigned long flags; |
293 | ||
294 | spin_lock_irqsave(&undef_lock, flags); | |
1da177e4 | 295 | list_del(&hook->node); |
109d89ca | 296 | spin_unlock_irqrestore(&undef_lock, flags); |
1da177e4 LT |
297 | } |
298 | ||
7ab3f8d5 | 299 | asmlinkage void __exception do_undefinstr(struct pt_regs *regs) |
1da177e4 LT |
300 | { |
301 | unsigned int correction = thumb_mode(regs) ? 2 : 4; | |
302 | unsigned int instr; | |
303 | struct undef_hook *hook; | |
304 | siginfo_t info; | |
305 | void __user *pc; | |
99cce8f7 | 306 | unsigned long flags; |
1da177e4 LT |
307 | |
308 | /* | |
309 | * According to the ARM ARM, PC is 2 or 4 bytes ahead, | |
310 | * depending whether we're in Thumb mode or not. | |
311 | * Correct this offset. | |
312 | */ | |
313 | regs->ARM_pc -= correction; | |
314 | ||
315 | pc = (void __user *)instruction_pointer(regs); | |
dfc544c7 DW |
316 | |
317 | if (processor_mode(regs) == SVC_MODE) { | |
318 | instr = *(u32 *) pc; | |
319 | } else if (thumb_mode(regs)) { | |
1da177e4 LT |
320 | get_user(instr, (u16 __user *)pc); |
321 | } else { | |
322 | get_user(instr, (u32 __user *)pc); | |
323 | } | |
324 | ||
99cce8f7 | 325 | spin_lock_irqsave(&undef_lock, flags); |
1da177e4 LT |
326 | list_for_each_entry(hook, &undef_hook, node) { |
327 | if ((instr & hook->instr_mask) == hook->instr_val && | |
328 | (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val) { | |
329 | if (hook->fn(regs, instr) == 0) { | |
aeb747af | 330 | spin_unlock_irqrestore(&undef_lock, flags); |
1da177e4 LT |
331 | return; |
332 | } | |
333 | } | |
334 | } | |
99cce8f7 | 335 | spin_unlock_irqrestore(&undef_lock, flags); |
1da177e4 LT |
336 | |
337 | #ifdef CONFIG_DEBUG_USER | |
338 | if (user_debug & UDBG_UNDEFINED) { | |
339 | printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n", | |
19c5870c | 340 | current->comm, task_pid_nr(current), pc); |
1da177e4 LT |
341 | dump_instr(regs); |
342 | } | |
343 | #endif | |
344 | ||
345 | info.si_signo = SIGILL; | |
346 | info.si_errno = 0; | |
347 | info.si_code = ILL_ILLOPC; | |
348 | info.si_addr = pc; | |
349 | ||
1eeb66a1 | 350 | arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6); |
1da177e4 LT |
351 | } |
352 | ||
353 | asmlinkage void do_unexp_fiq (struct pt_regs *regs) | |
354 | { | |
1da177e4 LT |
355 | printk("Hmm. Unexpected FIQ received, but trying to continue\n"); |
356 | printk("You may have a hardware problem...\n"); | |
1da177e4 LT |
357 | } |
358 | ||
359 | /* | |
360 | * bad_mode handles the impossible case in the vectors. If you see one of | |
361 | * these, then it's extremely serious, and could mean you have buggy hardware. | |
362 | * It never returns, and never tries to sync. We hope that we can at least | |
363 | * dump out some state information... | |
364 | */ | |
ae0a846e | 365 | asmlinkage void bad_mode(struct pt_regs *regs, int reason) |
1da177e4 LT |
366 | { |
367 | console_verbose(); | |
368 | ||
ae0a846e | 369 | printk(KERN_CRIT "Bad mode in %s handler detected\n", handler[reason]); |
1da177e4 LT |
370 | |
371 | die("Oops - bad mode", regs, 0); | |
372 | local_irq_disable(); | |
373 | panic("bad mode"); | |
374 | } | |
375 | ||
376 | static int bad_syscall(int n, struct pt_regs *regs) | |
377 | { | |
378 | struct thread_info *thread = current_thread_info(); | |
379 | siginfo_t info; | |
380 | ||
a999cb04 NP |
381 | if (current->personality != PER_LINUX && |
382 | current->personality != PER_LINUX_32BIT && | |
383 | thread->exec_domain->handler) { | |
1da177e4 LT |
384 | thread->exec_domain->handler(n, regs); |
385 | return regs->ARM_r0; | |
386 | } | |
387 | ||
388 | #ifdef CONFIG_DEBUG_USER | |
389 | if (user_debug & UDBG_SYSCALL) { | |
390 | printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n", | |
19c5870c | 391 | task_pid_nr(current), current->comm, n); |
1da177e4 LT |
392 | dump_instr(regs); |
393 | } | |
394 | #endif | |
395 | ||
396 | info.si_signo = SIGILL; | |
397 | info.si_errno = 0; | |
398 | info.si_code = ILL_ILLTRP; | |
399 | info.si_addr = (void __user *)instruction_pointer(regs) - | |
400 | (thumb_mode(regs) ? 2 : 4); | |
401 | ||
1eeb66a1 | 402 | arm_notify_die("Oops - bad syscall", regs, &info, n, 0); |
1da177e4 LT |
403 | |
404 | return regs->ARM_r0; | |
405 | } | |
406 | ||
407 | static inline void | |
408 | do_cache_op(unsigned long start, unsigned long end, int flags) | |
409 | { | |
410 | struct vm_area_struct *vma; | |
411 | ||
412 | if (end < start || flags) | |
413 | return; | |
414 | ||
415 | vma = find_vma(current->active_mm, start); | |
416 | if (vma && vma->vm_start < end) { | |
417 | if (start < vma->vm_start) | |
418 | start = vma->vm_start; | |
419 | if (end > vma->vm_end) | |
420 | end = vma->vm_end; | |
421 | ||
422 | flush_cache_user_range(vma, start, end); | |
423 | } | |
424 | } | |
425 | ||
426 | /* | |
427 | * Handle all unrecognised system calls. | |
428 | * 0x9f0000 - 0x9fffff are some more esoteric system calls | |
429 | */ | |
430 | #define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE) | |
431 | asmlinkage int arm_syscall(int no, struct pt_regs *regs) | |
432 | { | |
433 | struct thread_info *thread = current_thread_info(); | |
434 | siginfo_t info; | |
435 | ||
3f2829a3 | 436 | if ((no >> 16) != (__ARM_NR_BASE>> 16)) |
1da177e4 LT |
437 | return bad_syscall(no, regs); |
438 | ||
439 | switch (no & 0xffff) { | |
440 | case 0: /* branch through 0 */ | |
441 | info.si_signo = SIGSEGV; | |
442 | info.si_errno = 0; | |
443 | info.si_code = SEGV_MAPERR; | |
444 | info.si_addr = NULL; | |
445 | ||
1eeb66a1 | 446 | arm_notify_die("branch through zero", regs, &info, 0, 0); |
1da177e4 LT |
447 | return 0; |
448 | ||
449 | case NR(breakpoint): /* SWI BREAK_POINT */ | |
450 | regs->ARM_pc -= thumb_mode(regs) ? 2 : 4; | |
451 | ptrace_break(current, regs); | |
452 | return regs->ARM_r0; | |
453 | ||
454 | /* | |
455 | * Flush a region from virtual address 'r0' to virtual address 'r1' | |
456 | * _exclusive_. There is no alignment requirement on either address; | |
457 | * user space does not need to know the hardware cache layout. | |
458 | * | |
459 | * r2 contains flags. It should ALWAYS be passed as ZERO until it | |
460 | * is defined to be something else. For now we ignore it, but may | |
461 | * the fires of hell burn in your belly if you break this rule. ;) | |
462 | * | |
463 | * (at a later date, we may want to allow this call to not flush | |
464 | * various aspects of the cache. Passing '0' will guarantee that | |
465 | * everything necessary gets flushed to maintain consistency in | |
466 | * the specified region). | |
467 | */ | |
468 | case NR(cacheflush): | |
469 | do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2); | |
470 | return 0; | |
471 | ||
472 | case NR(usr26): | |
473 | if (!(elf_hwcap & HWCAP_26BIT)) | |
474 | break; | |
475 | regs->ARM_cpsr &= ~MODE32_BIT; | |
476 | return regs->ARM_r0; | |
477 | ||
478 | case NR(usr32): | |
479 | if (!(elf_hwcap & HWCAP_26BIT)) | |
480 | break; | |
481 | regs->ARM_cpsr |= MODE32_BIT; | |
482 | return regs->ARM_r0; | |
483 | ||
484 | case NR(set_tls): | |
485 | thread->tp_value = regs->ARM_r0; | |
4b0e07a5 | 486 | #if defined(CONFIG_HAS_TLS_REG) |
2d2669b6 | 487 | asm ("mcr p15, 0, %0, c13, c0, 3" : : "r" (regs->ARM_r0) ); |
4b0e07a5 | 488 | #elif !defined(CONFIG_TLS_REG_EMUL) |
1da177e4 | 489 | /* |
2d2669b6 NP |
490 | * User space must never try to access this directly. |
491 | * Expect your app to break eventually if you do so. | |
492 | * The user helper at 0xffff0fe0 must be used instead. | |
493 | * (see entry-armv.S for details) | |
1da177e4 | 494 | */ |
2d2669b6 NP |
495 | *((unsigned int *)0xffff0ff0) = regs->ARM_r0; |
496 | #endif | |
1da177e4 LT |
497 | return 0; |
498 | ||
dcef1f63 NP |
499 | #ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG |
500 | /* | |
501 | * Atomically store r1 in *r2 if *r2 is equal to r0 for user space. | |
502 | * Return zero in r0 if *MEM was changed or non-zero if no exchange | |
503 | * happened. Also set the user C flag accordingly. | |
504 | * If access permissions have to be fixed up then non-zero is | |
505 | * returned and the operation has to be re-attempted. | |
506 | * | |
507 | * *NOTE*: This is a ghost syscall private to the kernel. Only the | |
508 | * __kuser_cmpxchg code in entry-armv.S should be aware of its | |
509 | * existence. Don't ever use this from user code. | |
510 | */ | |
511 | case 0xfff0: | |
512 | { | |
513 | extern void do_DataAbort(unsigned long addr, unsigned int fsr, | |
514 | struct pt_regs *regs); | |
515 | unsigned long val; | |
516 | unsigned long addr = regs->ARM_r2; | |
517 | struct mm_struct *mm = current->mm; | |
518 | pgd_t *pgd; pmd_t *pmd; pte_t *pte; | |
69b04754 | 519 | spinlock_t *ptl; |
dcef1f63 NP |
520 | |
521 | regs->ARM_cpsr &= ~PSR_C_BIT; | |
69b04754 | 522 | down_read(&mm->mmap_sem); |
dcef1f63 NP |
523 | pgd = pgd_offset(mm, addr); |
524 | if (!pgd_present(*pgd)) | |
525 | goto bad_access; | |
526 | pmd = pmd_offset(pgd, addr); | |
527 | if (!pmd_present(*pmd)) | |
528 | goto bad_access; | |
69b04754 | 529 | pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
2ce9804f | 530 | if (!pte_present(*pte) || !pte_dirty(*pte)) { |
69b04754 | 531 | pte_unmap_unlock(pte, ptl); |
dcef1f63 | 532 | goto bad_access; |
69b04754 | 533 | } |
dcef1f63 NP |
534 | val = *(unsigned long *)addr; |
535 | val -= regs->ARM_r0; | |
536 | if (val == 0) { | |
537 | *(unsigned long *)addr = regs->ARM_r1; | |
538 | regs->ARM_cpsr |= PSR_C_BIT; | |
539 | } | |
69b04754 HD |
540 | pte_unmap_unlock(pte, ptl); |
541 | up_read(&mm->mmap_sem); | |
dcef1f63 NP |
542 | return val; |
543 | ||
544 | bad_access: | |
69b04754 | 545 | up_read(&mm->mmap_sem); |
74f88494 | 546 | /* simulate a write access fault */ |
dcef1f63 NP |
547 | do_DataAbort(addr, 15 + (1 << 11), regs); |
548 | return -1; | |
549 | } | |
550 | #endif | |
551 | ||
1da177e4 LT |
552 | default: |
553 | /* Calls 9f00xx..9f07ff are defined to return -ENOSYS | |
554 | if not implemented, rather than raising SIGILL. This | |
555 | way the calling program can gracefully determine whether | |
556 | a feature is supported. */ | |
557 | if (no <= 0x7ff) | |
558 | return -ENOSYS; | |
559 | break; | |
560 | } | |
561 | #ifdef CONFIG_DEBUG_USER | |
562 | /* | |
563 | * experience shows that these seem to indicate that | |
564 | * something catastrophic has happened | |
565 | */ | |
566 | if (user_debug & UDBG_SYSCALL) { | |
567 | printk("[%d] %s: arm syscall %d\n", | |
19c5870c | 568 | task_pid_nr(current), current->comm, no); |
1da177e4 LT |
569 | dump_instr(regs); |
570 | if (user_mode(regs)) { | |
652a12ef | 571 | __show_regs(regs); |
1da177e4 LT |
572 | c_backtrace(regs->ARM_fp, processor_mode(regs)); |
573 | } | |
574 | } | |
575 | #endif | |
576 | info.si_signo = SIGILL; | |
577 | info.si_errno = 0; | |
578 | info.si_code = ILL_ILLTRP; | |
579 | info.si_addr = (void __user *)instruction_pointer(regs) - | |
580 | (thumb_mode(regs) ? 2 : 4); | |
581 | ||
1eeb66a1 | 582 | arm_notify_die("Oops - bad syscall(2)", regs, &info, no, 0); |
1da177e4 LT |
583 | return 0; |
584 | } | |
585 | ||
4b0e07a5 | 586 | #ifdef CONFIG_TLS_REG_EMUL |
2d2669b6 NP |
587 | |
588 | /* | |
589 | * We might be running on an ARMv6+ processor which should have the TLS | |
4b0e07a5 NP |
590 | * register but for some reason we can't use it, or maybe an SMP system |
591 | * using a pre-ARMv6 processor (there are apparently a few prototypes like | |
592 | * that in existence) and therefore access to that register must be | |
593 | * emulated. | |
2d2669b6 NP |
594 | */ |
595 | ||
596 | static int get_tp_trap(struct pt_regs *regs, unsigned int instr) | |
597 | { | |
598 | int reg = (instr >> 12) & 15; | |
599 | if (reg == 15) | |
600 | return 1; | |
601 | regs->uregs[reg] = current_thread_info()->tp_value; | |
602 | regs->ARM_pc += 4; | |
603 | return 0; | |
604 | } | |
605 | ||
606 | static struct undef_hook arm_mrc_hook = { | |
607 | .instr_mask = 0x0fff0fff, | |
608 | .instr_val = 0x0e1d0f70, | |
609 | .cpsr_mask = PSR_T_BIT, | |
610 | .cpsr_val = 0, | |
611 | .fn = get_tp_trap, | |
612 | }; | |
613 | ||
614 | static int __init arm_mrc_hook_init(void) | |
615 | { | |
616 | register_undef_hook(&arm_mrc_hook); | |
617 | return 0; | |
618 | } | |
619 | ||
620 | late_initcall(arm_mrc_hook_init); | |
621 | ||
622 | #endif | |
623 | ||
1da177e4 LT |
624 | void __bad_xchg(volatile void *ptr, int size) |
625 | { | |
626 | printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n", | |
627 | __builtin_return_address(0), ptr, size); | |
628 | BUG(); | |
629 | } | |
630 | EXPORT_SYMBOL(__bad_xchg); | |
631 | ||
632 | /* | |
633 | * A data abort trap was taken, but we did not handle the instruction. | |
634 | * Try to abort the user program, or panic if it was the kernel. | |
635 | */ | |
636 | asmlinkage void | |
637 | baddataabort(int code, unsigned long instr, struct pt_regs *regs) | |
638 | { | |
639 | unsigned long addr = instruction_pointer(regs); | |
640 | siginfo_t info; | |
641 | ||
642 | #ifdef CONFIG_DEBUG_USER | |
643 | if (user_debug & UDBG_BADABORT) { | |
644 | printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n", | |
19c5870c | 645 | task_pid_nr(current), current->comm, code, instr); |
1da177e4 LT |
646 | dump_instr(regs); |
647 | show_pte(current->mm, addr); | |
648 | } | |
649 | #endif | |
650 | ||
651 | info.si_signo = SIGILL; | |
652 | info.si_errno = 0; | |
653 | info.si_code = ILL_ILLOPC; | |
654 | info.si_addr = (void __user *)addr; | |
655 | ||
1eeb66a1 | 656 | arm_notify_die("unknown data abort code", regs, &info, instr, 0); |
1da177e4 LT |
657 | } |
658 | ||
7174d852 | 659 | void __attribute__((noreturn)) __bug(const char *file, int line) |
1da177e4 | 660 | { |
7174d852 | 661 | printk(KERN_CRIT"kernel BUG at %s:%d!\n", file, line); |
1da177e4 | 662 | *(int *)0 = 0; |
6a1ced59 CM |
663 | |
664 | /* Avoid "noreturn function does return" */ | |
665 | for (;;); | |
1da177e4 LT |
666 | } |
667 | EXPORT_SYMBOL(__bug); | |
668 | ||
669 | void __readwrite_bug(const char *fn) | |
670 | { | |
671 | printk("%s called, but not implemented\n", fn); | |
672 | BUG(); | |
673 | } | |
674 | EXPORT_SYMBOL(__readwrite_bug); | |
675 | ||
676 | void __pte_error(const char *file, int line, unsigned long val) | |
677 | { | |
678 | printk("%s:%d: bad pte %08lx.\n", file, line, val); | |
679 | } | |
680 | ||
681 | void __pmd_error(const char *file, int line, unsigned long val) | |
682 | { | |
683 | printk("%s:%d: bad pmd %08lx.\n", file, line, val); | |
684 | } | |
685 | ||
686 | void __pgd_error(const char *file, int line, unsigned long val) | |
687 | { | |
688 | printk("%s:%d: bad pgd %08lx.\n", file, line, val); | |
689 | } | |
690 | ||
691 | asmlinkage void __div0(void) | |
692 | { | |
693 | printk("Division by zero in kernel.\n"); | |
694 | dump_stack(); | |
695 | } | |
696 | EXPORT_SYMBOL(__div0); | |
697 | ||
698 | void abort(void) | |
699 | { | |
700 | BUG(); | |
701 | ||
702 | /* if that doesn't kill us, halt */ | |
703 | panic("Oops failed to kill thread"); | |
704 | } | |
705 | EXPORT_SYMBOL(abort); | |
706 | ||
707 | void __init trap_init(void) | |
708 | { | |
c760fc19 | 709 | unsigned long vectors = CONFIG_VECTORS_BASE; |
7933523d RK |
710 | extern char __stubs_start[], __stubs_end[]; |
711 | extern char __vectors_start[], __vectors_end[]; | |
2d2669b6 NP |
712 | extern char __kuser_helper_start[], __kuser_helper_end[]; |
713 | int kuser_sz = __kuser_helper_end - __kuser_helper_start; | |
1da177e4 | 714 | |
7933523d | 715 | /* |
2d2669b6 NP |
716 | * Copy the vectors, stubs and kuser helpers (in entry-armv.S) |
717 | * into the vector page, mapped at 0xffff0000, and ensure these | |
718 | * are visible to the instruction stream. | |
7933523d | 719 | */ |
c760fc19 HC |
720 | memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start); |
721 | memcpy((void *)vectors + 0x200, __stubs_start, __stubs_end - __stubs_start); | |
722 | memcpy((void *)vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz); | |
e00d349e RK |
723 | |
724 | /* | |
725 | * Copy signal return handlers into the vector page, and | |
726 | * set sigreturn to be a pointer to these. | |
727 | */ | |
728 | memcpy((void *)KERN_SIGRETURN_CODE, sigreturn_codes, | |
729 | sizeof(sigreturn_codes)); | |
730 | ||
c760fc19 | 731 | flush_icache_range(vectors, vectors + PAGE_SIZE); |
1da177e4 LT |
732 | modify_domain(DOMAIN_USER, DOMAIN_CLIENT); |
733 | } |