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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> |
67306da6 | 21 | #include <linux/hardirq.h> |
1da177e4 | 22 | #include <linux/init.h> |
33fa9b13 | 23 | #include <linux/uaccess.h> |
1da177e4 LT |
24 | |
25 | #include <asm/atomic.h> | |
26 | #include <asm/cacheflush.h> | |
1da177e4 | 27 | #include <asm/system.h> |
1da177e4 LT |
28 | #include <asm/unistd.h> |
29 | #include <asm/traps.h> | |
bff595c1 | 30 | #include <asm/unwind.h> |
1da177e4 LT |
31 | |
32 | #include "ptrace.h" | |
e00d349e | 33 | #include "signal.h" |
1da177e4 | 34 | |
1da177e4 LT |
35 | static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" }; |
36 | ||
37 | #ifdef CONFIG_DEBUG_USER | |
38 | unsigned int user_debug; | |
39 | ||
40 | static int __init user_debug_setup(char *str) | |
41 | { | |
42 | get_option(&str, &user_debug); | |
43 | return 1; | |
44 | } | |
45 | __setup("user_debug=", user_debug_setup); | |
46 | #endif | |
47 | ||
7ab3f8d5 RK |
48 | static void dump_mem(const char *str, unsigned long bottom, unsigned long top); |
49 | ||
7ab3f8d5 | 50 | void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame) |
1da177e4 LT |
51 | { |
52 | #ifdef CONFIG_KALLSYMS | |
53 | printk("[<%08lx>] ", where); | |
54 | print_symbol("(%s) ", where); | |
55 | printk("from [<%08lx>] ", from); | |
56 | print_symbol("(%s)\n", from); | |
57 | #else | |
58 | printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from); | |
59 | #endif | |
7ab3f8d5 RK |
60 | |
61 | if (in_exception_text(where)) | |
62 | dump_mem("Exception stack", frame + 4, frame + 4 + sizeof(struct pt_regs)); | |
1da177e4 LT |
63 | } |
64 | ||
bff595c1 | 65 | #ifndef CONFIG_ARM_UNWIND |
1da177e4 LT |
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 | { | |
09d9bae0 RK |
73 | if (sp < PAGE_OFFSET || |
74 | (sp > (unsigned long)high_memory && high_memory != NULL)) | |
1da177e4 LT |
75 | return -EFAULT; |
76 | ||
77 | return 0; | |
78 | } | |
bff595c1 | 79 | #endif |
1da177e4 LT |
80 | |
81 | /* | |
82 | * Dump out the contents of some memory nicely... | |
83 | */ | |
84 | static void dump_mem(const char *str, unsigned long bottom, unsigned long top) | |
85 | { | |
86 | unsigned long p = bottom & ~31; | |
87 | mm_segment_t fs; | |
88 | int i; | |
89 | ||
90 | /* | |
91 | * We need to switch to kernel mode so that we can use __get_user | |
92 | * to safely read from kernel space. Note that we now dump the | |
93 | * code first, just in case the backtrace kills us. | |
94 | */ | |
95 | fs = get_fs(); | |
96 | set_fs(KERNEL_DS); | |
97 | ||
98 | printk("%s(0x%08lx to 0x%08lx)\n", str, bottom, top); | |
99 | ||
100 | for (p = bottom & ~31; p < top;) { | |
101 | printk("%04lx: ", p & 0xffff); | |
102 | ||
103 | for (i = 0; i < 8; i++, p += 4) { | |
104 | unsigned int val; | |
105 | ||
106 | if (p < bottom || p >= top) | |
107 | printk(" "); | |
108 | else { | |
109 | __get_user(val, (unsigned long *)p); | |
110 | printk("%08x ", val); | |
111 | } | |
112 | } | |
113 | printk ("\n"); | |
114 | } | |
115 | ||
116 | set_fs(fs); | |
117 | } | |
118 | ||
119 | static void dump_instr(struct pt_regs *regs) | |
120 | { | |
121 | unsigned long addr = instruction_pointer(regs); | |
122 | const int thumb = thumb_mode(regs); | |
123 | const int width = thumb ? 4 : 8; | |
124 | mm_segment_t fs; | |
125 | int i; | |
126 | ||
127 | /* | |
128 | * We need to switch to kernel mode so that we can use __get_user | |
129 | * to safely read from kernel space. Note that we now dump the | |
130 | * code first, just in case the backtrace kills us. | |
131 | */ | |
132 | fs = get_fs(); | |
133 | set_fs(KERNEL_DS); | |
134 | ||
135 | printk("Code: "); | |
136 | for (i = -4; i < 1; i++) { | |
137 | unsigned int val, bad; | |
138 | ||
139 | if (thumb) | |
140 | bad = __get_user(val, &((u16 *)addr)[i]); | |
141 | else | |
142 | bad = __get_user(val, &((u32 *)addr)[i]); | |
143 | ||
144 | if (!bad) | |
145 | printk(i == 0 ? "(%0*x) " : "%0*x ", width, val); | |
146 | else { | |
147 | printk("bad PC value."); | |
148 | break; | |
149 | } | |
150 | } | |
151 | printk("\n"); | |
152 | ||
153 | set_fs(fs); | |
154 | } | |
155 | ||
bff595c1 CM |
156 | #ifdef CONFIG_ARM_UNWIND |
157 | static inline void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) | |
158 | { | |
159 | unwind_backtrace(regs, tsk); | |
160 | } | |
161 | #else | |
1da177e4 LT |
162 | static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) |
163 | { | |
67a94c23 | 164 | unsigned int fp, mode; |
1da177e4 LT |
165 | int ok = 1; |
166 | ||
167 | printk("Backtrace: "); | |
67a94c23 CM |
168 | |
169 | if (!tsk) | |
170 | tsk = current; | |
171 | ||
172 | if (regs) { | |
173 | fp = regs->ARM_fp; | |
174 | mode = processor_mode(regs); | |
175 | } else if (tsk != current) { | |
176 | fp = thread_saved_fp(tsk); | |
177 | mode = 0x10; | |
178 | } else { | |
179 | asm("mov %0, fp" : "=r" (fp) : : "cc"); | |
180 | mode = 0x10; | |
181 | } | |
182 | ||
1da177e4 LT |
183 | if (!fp) { |
184 | printk("no frame pointer"); | |
185 | ok = 0; | |
186 | } else if (verify_stack(fp)) { | |
187 | printk("invalid frame pointer 0x%08x", fp); | |
188 | ok = 0; | |
55205823 | 189 | } else if (fp < (unsigned long)end_of_stack(tsk)) |
1da177e4 LT |
190 | printk("frame pointer underflow"); |
191 | printk("\n"); | |
192 | ||
193 | if (ok) | |
67a94c23 | 194 | c_backtrace(fp, mode); |
1da177e4 | 195 | } |
bff595c1 | 196 | #endif |
1da177e4 LT |
197 | |
198 | void dump_stack(void) | |
199 | { | |
67a94c23 | 200 | dump_backtrace(NULL, NULL); |
1da177e4 LT |
201 | } |
202 | ||
203 | EXPORT_SYMBOL(dump_stack); | |
204 | ||
205 | void show_stack(struct task_struct *tsk, unsigned long *sp) | |
206 | { | |
67a94c23 | 207 | dump_backtrace(NULL, tsk); |
1da177e4 LT |
208 | barrier(); |
209 | } | |
210 | ||
d9202429 RK |
211 | #ifdef CONFIG_PREEMPT |
212 | #define S_PREEMPT " PREEMPT" | |
213 | #else | |
214 | #define S_PREEMPT "" | |
215 | #endif | |
216 | #ifdef CONFIG_SMP | |
217 | #define S_SMP " SMP" | |
218 | #else | |
219 | #define S_SMP "" | |
220 | #endif | |
221 | ||
d362979a | 222 | static void __die(const char *str, int err, struct thread_info *thread, struct pt_regs *regs) |
1da177e4 | 223 | { |
d362979a | 224 | struct task_struct *tsk = thread->task; |
1da177e4 LT |
225 | static int die_counter; |
226 | ||
d9202429 RK |
227 | printk("Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n", |
228 | str, err, ++die_counter); | |
1da177e4 | 229 | print_modules(); |
652a12ef | 230 | __show_regs(regs); |
1da177e4 | 231 | printk("Process %s (pid: %d, stack limit = 0x%p)\n", |
19c5870c | 232 | tsk->comm, task_pid_nr(tsk), thread + 1); |
1da177e4 LT |
233 | |
234 | if (!user_mode(regs) || in_interrupt()) { | |
4f7a1812 | 235 | dump_mem("Stack: ", regs->ARM_sp, |
32d39a93 | 236 | THREAD_SIZE + (unsigned long)task_stack_page(tsk)); |
1da177e4 LT |
237 | dump_backtrace(regs, tsk); |
238 | dump_instr(regs); | |
239 | } | |
d362979a | 240 | } |
1da177e4 | 241 | |
d362979a RK |
242 | DEFINE_SPINLOCK(die_lock); |
243 | ||
244 | /* | |
245 | * This function is protected against re-entrancy. | |
246 | */ | |
247 | NORET_TYPE void die(const char *str, struct pt_regs *regs, int err) | |
248 | { | |
249 | struct thread_info *thread = current_thread_info(); | |
250 | ||
d9202429 RK |
251 | oops_enter(); |
252 | ||
d362979a RK |
253 | console_verbose(); |
254 | spin_lock_irq(&die_lock); | |
255 | bust_spinlocks(1); | |
256 | __die(str, err, thread, regs); | |
1da177e4 | 257 | bust_spinlocks(0); |
bcdcd8e7 | 258 | add_taint(TAINT_DIE); |
1da177e4 | 259 | spin_unlock_irq(&die_lock); |
31867499 | 260 | |
d9202429 RK |
261 | if (in_interrupt()) |
262 | panic("Fatal exception in interrupt"); | |
263 | ||
cea6a4ba | 264 | if (panic_on_oops) |
012c437d | 265 | panic("Fatal exception"); |
31867499 | 266 | |
d9202429 | 267 | oops_exit(); |
1da177e4 LT |
268 | do_exit(SIGSEGV); |
269 | } | |
270 | ||
1eeb66a1 CH |
271 | void arm_notify_die(const char *str, struct pt_regs *regs, |
272 | struct siginfo *info, unsigned long err, unsigned long trap) | |
1da177e4 LT |
273 | { |
274 | if (user_mode(regs)) { | |
275 | current->thread.error_code = err; | |
276 | current->thread.trap_no = trap; | |
277 | ||
278 | force_sig_info(info->si_signo, info, current); | |
279 | } else { | |
280 | die(str, regs, err); | |
281 | } | |
282 | } | |
283 | ||
284 | static LIST_HEAD(undef_hook); | |
285 | static DEFINE_SPINLOCK(undef_lock); | |
286 | ||
287 | void register_undef_hook(struct undef_hook *hook) | |
288 | { | |
109d89ca RK |
289 | unsigned long flags; |
290 | ||
291 | spin_lock_irqsave(&undef_lock, flags); | |
1da177e4 | 292 | list_add(&hook->node, &undef_hook); |
109d89ca | 293 | spin_unlock_irqrestore(&undef_lock, flags); |
1da177e4 LT |
294 | } |
295 | ||
296 | void unregister_undef_hook(struct undef_hook *hook) | |
297 | { | |
109d89ca RK |
298 | unsigned long flags; |
299 | ||
300 | spin_lock_irqsave(&undef_lock, flags); | |
1da177e4 | 301 | list_del(&hook->node); |
109d89ca | 302 | spin_unlock_irqrestore(&undef_lock, flags); |
1da177e4 LT |
303 | } |
304 | ||
b03a5b75 RK |
305 | static int call_undef_hook(struct pt_regs *regs, unsigned int instr) |
306 | { | |
307 | struct undef_hook *hook; | |
308 | unsigned long flags; | |
309 | int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL; | |
310 | ||
311 | spin_lock_irqsave(&undef_lock, flags); | |
312 | list_for_each_entry(hook, &undef_hook, node) | |
313 | if ((instr & hook->instr_mask) == hook->instr_val && | |
314 | (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val) | |
315 | fn = hook->fn; | |
316 | spin_unlock_irqrestore(&undef_lock, flags); | |
317 | ||
318 | return fn ? fn(regs, instr) : 1; | |
319 | } | |
320 | ||
7ab3f8d5 | 321 | asmlinkage void __exception do_undefinstr(struct pt_regs *regs) |
1da177e4 LT |
322 | { |
323 | unsigned int correction = thumb_mode(regs) ? 2 : 4; | |
324 | unsigned int instr; | |
1da177e4 LT |
325 | siginfo_t info; |
326 | void __user *pc; | |
327 | ||
328 | /* | |
329 | * According to the ARM ARM, PC is 2 or 4 bytes ahead, | |
330 | * depending whether we're in Thumb mode or not. | |
331 | * Correct this offset. | |
332 | */ | |
333 | regs->ARM_pc -= correction; | |
334 | ||
335 | pc = (void __user *)instruction_pointer(regs); | |
dfc544c7 DW |
336 | |
337 | if (processor_mode(regs) == SVC_MODE) { | |
338 | instr = *(u32 *) pc; | |
339 | } else if (thumb_mode(regs)) { | |
1da177e4 LT |
340 | get_user(instr, (u16 __user *)pc); |
341 | } else { | |
342 | get_user(instr, (u32 __user *)pc); | |
343 | } | |
344 | ||
b03a5b75 RK |
345 | if (call_undef_hook(regs, instr) == 0) |
346 | return; | |
1da177e4 LT |
347 | |
348 | #ifdef CONFIG_DEBUG_USER | |
349 | if (user_debug & UDBG_UNDEFINED) { | |
350 | printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n", | |
19c5870c | 351 | current->comm, task_pid_nr(current), pc); |
1da177e4 LT |
352 | dump_instr(regs); |
353 | } | |
354 | #endif | |
355 | ||
356 | info.si_signo = SIGILL; | |
357 | info.si_errno = 0; | |
358 | info.si_code = ILL_ILLOPC; | |
359 | info.si_addr = pc; | |
360 | ||
1eeb66a1 | 361 | arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6); |
1da177e4 LT |
362 | } |
363 | ||
364 | asmlinkage void do_unexp_fiq (struct pt_regs *regs) | |
365 | { | |
1da177e4 LT |
366 | printk("Hmm. Unexpected FIQ received, but trying to continue\n"); |
367 | printk("You may have a hardware problem...\n"); | |
1da177e4 LT |
368 | } |
369 | ||
370 | /* | |
371 | * bad_mode handles the impossible case in the vectors. If you see one of | |
372 | * these, then it's extremely serious, and could mean you have buggy hardware. | |
373 | * It never returns, and never tries to sync. We hope that we can at least | |
374 | * dump out some state information... | |
375 | */ | |
ae0a846e | 376 | asmlinkage void bad_mode(struct pt_regs *regs, int reason) |
1da177e4 LT |
377 | { |
378 | console_verbose(); | |
379 | ||
ae0a846e | 380 | printk(KERN_CRIT "Bad mode in %s handler detected\n", handler[reason]); |
1da177e4 LT |
381 | |
382 | die("Oops - bad mode", regs, 0); | |
383 | local_irq_disable(); | |
384 | panic("bad mode"); | |
385 | } | |
386 | ||
387 | static int bad_syscall(int n, struct pt_regs *regs) | |
388 | { | |
389 | struct thread_info *thread = current_thread_info(); | |
390 | siginfo_t info; | |
391 | ||
a999cb04 NP |
392 | if (current->personality != PER_LINUX && |
393 | current->personality != PER_LINUX_32BIT && | |
394 | thread->exec_domain->handler) { | |
1da177e4 LT |
395 | thread->exec_domain->handler(n, regs); |
396 | return regs->ARM_r0; | |
397 | } | |
398 | ||
399 | #ifdef CONFIG_DEBUG_USER | |
400 | if (user_debug & UDBG_SYSCALL) { | |
401 | printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n", | |
19c5870c | 402 | task_pid_nr(current), current->comm, n); |
1da177e4 LT |
403 | dump_instr(regs); |
404 | } | |
405 | #endif | |
406 | ||
407 | info.si_signo = SIGILL; | |
408 | info.si_errno = 0; | |
409 | info.si_code = ILL_ILLTRP; | |
410 | info.si_addr = (void __user *)instruction_pointer(regs) - | |
411 | (thumb_mode(regs) ? 2 : 4); | |
412 | ||
1eeb66a1 | 413 | arm_notify_die("Oops - bad syscall", regs, &info, n, 0); |
1da177e4 LT |
414 | |
415 | return regs->ARM_r0; | |
416 | } | |
417 | ||
418 | static inline void | |
419 | do_cache_op(unsigned long start, unsigned long end, int flags) | |
420 | { | |
421 | struct vm_area_struct *vma; | |
422 | ||
423 | if (end < start || flags) | |
424 | return; | |
425 | ||
426 | vma = find_vma(current->active_mm, start); | |
427 | if (vma && vma->vm_start < end) { | |
428 | if (start < vma->vm_start) | |
429 | start = vma->vm_start; | |
430 | if (end > vma->vm_end) | |
431 | end = vma->vm_end; | |
432 | ||
433 | flush_cache_user_range(vma, start, end); | |
434 | } | |
435 | } | |
436 | ||
437 | /* | |
438 | * Handle all unrecognised system calls. | |
439 | * 0x9f0000 - 0x9fffff are some more esoteric system calls | |
440 | */ | |
441 | #define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE) | |
442 | asmlinkage int arm_syscall(int no, struct pt_regs *regs) | |
443 | { | |
444 | struct thread_info *thread = current_thread_info(); | |
445 | siginfo_t info; | |
446 | ||
3f2829a3 | 447 | if ((no >> 16) != (__ARM_NR_BASE>> 16)) |
1da177e4 LT |
448 | return bad_syscall(no, regs); |
449 | ||
450 | switch (no & 0xffff) { | |
451 | case 0: /* branch through 0 */ | |
452 | info.si_signo = SIGSEGV; | |
453 | info.si_errno = 0; | |
454 | info.si_code = SEGV_MAPERR; | |
455 | info.si_addr = NULL; | |
456 | ||
1eeb66a1 | 457 | arm_notify_die("branch through zero", regs, &info, 0, 0); |
1da177e4 LT |
458 | return 0; |
459 | ||
460 | case NR(breakpoint): /* SWI BREAK_POINT */ | |
461 | regs->ARM_pc -= thumb_mode(regs) ? 2 : 4; | |
462 | ptrace_break(current, regs); | |
463 | return regs->ARM_r0; | |
464 | ||
465 | /* | |
466 | * Flush a region from virtual address 'r0' to virtual address 'r1' | |
467 | * _exclusive_. There is no alignment requirement on either address; | |
468 | * user space does not need to know the hardware cache layout. | |
469 | * | |
470 | * r2 contains flags. It should ALWAYS be passed as ZERO until it | |
471 | * is defined to be something else. For now we ignore it, but may | |
472 | * the fires of hell burn in your belly if you break this rule. ;) | |
473 | * | |
474 | * (at a later date, we may want to allow this call to not flush | |
475 | * various aspects of the cache. Passing '0' will guarantee that | |
476 | * everything necessary gets flushed to maintain consistency in | |
477 | * the specified region). | |
478 | */ | |
479 | case NR(cacheflush): | |
480 | do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2); | |
481 | return 0; | |
482 | ||
483 | case NR(usr26): | |
484 | if (!(elf_hwcap & HWCAP_26BIT)) | |
485 | break; | |
486 | regs->ARM_cpsr &= ~MODE32_BIT; | |
487 | return regs->ARM_r0; | |
488 | ||
489 | case NR(usr32): | |
490 | if (!(elf_hwcap & HWCAP_26BIT)) | |
491 | break; | |
492 | regs->ARM_cpsr |= MODE32_BIT; | |
493 | return regs->ARM_r0; | |
494 | ||
495 | case NR(set_tls): | |
496 | thread->tp_value = regs->ARM_r0; | |
4b0e07a5 | 497 | #if defined(CONFIG_HAS_TLS_REG) |
2d2669b6 | 498 | asm ("mcr p15, 0, %0, c13, c0, 3" : : "r" (regs->ARM_r0) ); |
4b0e07a5 | 499 | #elif !defined(CONFIG_TLS_REG_EMUL) |
1da177e4 | 500 | /* |
2d2669b6 NP |
501 | * User space must never try to access this directly. |
502 | * Expect your app to break eventually if you do so. | |
503 | * The user helper at 0xffff0fe0 must be used instead. | |
504 | * (see entry-armv.S for details) | |
1da177e4 | 505 | */ |
2d2669b6 NP |
506 | *((unsigned int *)0xffff0ff0) = regs->ARM_r0; |
507 | #endif | |
1da177e4 LT |
508 | return 0; |
509 | ||
dcef1f63 NP |
510 | #ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG |
511 | /* | |
512 | * Atomically store r1 in *r2 if *r2 is equal to r0 for user space. | |
513 | * Return zero in r0 if *MEM was changed or non-zero if no exchange | |
514 | * happened. Also set the user C flag accordingly. | |
515 | * If access permissions have to be fixed up then non-zero is | |
516 | * returned and the operation has to be re-attempted. | |
517 | * | |
518 | * *NOTE*: This is a ghost syscall private to the kernel. Only the | |
519 | * __kuser_cmpxchg code in entry-armv.S should be aware of its | |
520 | * existence. Don't ever use this from user code. | |
521 | */ | |
522 | case 0xfff0: | |
b49c0f24 | 523 | for (;;) { |
dcef1f63 NP |
524 | extern void do_DataAbort(unsigned long addr, unsigned int fsr, |
525 | struct pt_regs *regs); | |
526 | unsigned long val; | |
527 | unsigned long addr = regs->ARM_r2; | |
528 | struct mm_struct *mm = current->mm; | |
529 | pgd_t *pgd; pmd_t *pmd; pte_t *pte; | |
69b04754 | 530 | spinlock_t *ptl; |
dcef1f63 NP |
531 | |
532 | regs->ARM_cpsr &= ~PSR_C_BIT; | |
69b04754 | 533 | down_read(&mm->mmap_sem); |
dcef1f63 NP |
534 | pgd = pgd_offset(mm, addr); |
535 | if (!pgd_present(*pgd)) | |
536 | goto bad_access; | |
537 | pmd = pmd_offset(pgd, addr); | |
538 | if (!pmd_present(*pmd)) | |
539 | goto bad_access; | |
69b04754 | 540 | pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
2ce9804f | 541 | if (!pte_present(*pte) || !pte_dirty(*pte)) { |
69b04754 | 542 | pte_unmap_unlock(pte, ptl); |
dcef1f63 | 543 | goto bad_access; |
69b04754 | 544 | } |
dcef1f63 NP |
545 | val = *(unsigned long *)addr; |
546 | val -= regs->ARM_r0; | |
547 | if (val == 0) { | |
548 | *(unsigned long *)addr = regs->ARM_r1; | |
549 | regs->ARM_cpsr |= PSR_C_BIT; | |
550 | } | |
69b04754 HD |
551 | pte_unmap_unlock(pte, ptl); |
552 | up_read(&mm->mmap_sem); | |
dcef1f63 NP |
553 | return val; |
554 | ||
555 | bad_access: | |
69b04754 | 556 | up_read(&mm->mmap_sem); |
74f88494 | 557 | /* simulate a write access fault */ |
dcef1f63 | 558 | do_DataAbort(addr, 15 + (1 << 11), regs); |
dcef1f63 NP |
559 | } |
560 | #endif | |
561 | ||
1da177e4 LT |
562 | default: |
563 | /* Calls 9f00xx..9f07ff are defined to return -ENOSYS | |
564 | if not implemented, rather than raising SIGILL. This | |
565 | way the calling program can gracefully determine whether | |
566 | a feature is supported. */ | |
567 | if (no <= 0x7ff) | |
568 | return -ENOSYS; | |
569 | break; | |
570 | } | |
571 | #ifdef CONFIG_DEBUG_USER | |
572 | /* | |
573 | * experience shows that these seem to indicate that | |
574 | * something catastrophic has happened | |
575 | */ | |
576 | if (user_debug & UDBG_SYSCALL) { | |
577 | printk("[%d] %s: arm syscall %d\n", | |
19c5870c | 578 | task_pid_nr(current), current->comm, no); |
1da177e4 LT |
579 | dump_instr(regs); |
580 | if (user_mode(regs)) { | |
652a12ef | 581 | __show_regs(regs); |
1da177e4 LT |
582 | c_backtrace(regs->ARM_fp, processor_mode(regs)); |
583 | } | |
584 | } | |
585 | #endif | |
586 | info.si_signo = SIGILL; | |
587 | info.si_errno = 0; | |
588 | info.si_code = ILL_ILLTRP; | |
589 | info.si_addr = (void __user *)instruction_pointer(regs) - | |
590 | (thumb_mode(regs) ? 2 : 4); | |
591 | ||
1eeb66a1 | 592 | arm_notify_die("Oops - bad syscall(2)", regs, &info, no, 0); |
1da177e4 LT |
593 | return 0; |
594 | } | |
595 | ||
4b0e07a5 | 596 | #ifdef CONFIG_TLS_REG_EMUL |
2d2669b6 NP |
597 | |
598 | /* | |
599 | * We might be running on an ARMv6+ processor which should have the TLS | |
4b0e07a5 NP |
600 | * register but for some reason we can't use it, or maybe an SMP system |
601 | * using a pre-ARMv6 processor (there are apparently a few prototypes like | |
602 | * that in existence) and therefore access to that register must be | |
603 | * emulated. | |
2d2669b6 NP |
604 | */ |
605 | ||
606 | static int get_tp_trap(struct pt_regs *regs, unsigned int instr) | |
607 | { | |
608 | int reg = (instr >> 12) & 15; | |
609 | if (reg == 15) | |
610 | return 1; | |
611 | regs->uregs[reg] = current_thread_info()->tp_value; | |
612 | regs->ARM_pc += 4; | |
613 | return 0; | |
614 | } | |
615 | ||
616 | static struct undef_hook arm_mrc_hook = { | |
617 | .instr_mask = 0x0fff0fff, | |
618 | .instr_val = 0x0e1d0f70, | |
619 | .cpsr_mask = PSR_T_BIT, | |
620 | .cpsr_val = 0, | |
621 | .fn = get_tp_trap, | |
622 | }; | |
623 | ||
624 | static int __init arm_mrc_hook_init(void) | |
625 | { | |
626 | register_undef_hook(&arm_mrc_hook); | |
627 | return 0; | |
628 | } | |
629 | ||
630 | late_initcall(arm_mrc_hook_init); | |
631 | ||
632 | #endif | |
633 | ||
1da177e4 LT |
634 | void __bad_xchg(volatile void *ptr, int size) |
635 | { | |
636 | printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n", | |
637 | __builtin_return_address(0), ptr, size); | |
638 | BUG(); | |
639 | } | |
640 | EXPORT_SYMBOL(__bad_xchg); | |
641 | ||
642 | /* | |
643 | * A data abort trap was taken, but we did not handle the instruction. | |
644 | * Try to abort the user program, or panic if it was the kernel. | |
645 | */ | |
646 | asmlinkage void | |
647 | baddataabort(int code, unsigned long instr, struct pt_regs *regs) | |
648 | { | |
649 | unsigned long addr = instruction_pointer(regs); | |
650 | siginfo_t info; | |
651 | ||
652 | #ifdef CONFIG_DEBUG_USER | |
653 | if (user_debug & UDBG_BADABORT) { | |
654 | printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n", | |
19c5870c | 655 | task_pid_nr(current), current->comm, code, instr); |
1da177e4 LT |
656 | dump_instr(regs); |
657 | show_pte(current->mm, addr); | |
658 | } | |
659 | #endif | |
660 | ||
661 | info.si_signo = SIGILL; | |
662 | info.si_errno = 0; | |
663 | info.si_code = ILL_ILLOPC; | |
664 | info.si_addr = (void __user *)addr; | |
665 | ||
1eeb66a1 | 666 | arm_notify_die("unknown data abort code", regs, &info, instr, 0); |
1da177e4 LT |
667 | } |
668 | ||
7174d852 | 669 | void __attribute__((noreturn)) __bug(const char *file, int line) |
1da177e4 | 670 | { |
7174d852 | 671 | printk(KERN_CRIT"kernel BUG at %s:%d!\n", file, line); |
1da177e4 | 672 | *(int *)0 = 0; |
6a1ced59 CM |
673 | |
674 | /* Avoid "noreturn function does return" */ | |
675 | for (;;); | |
1da177e4 LT |
676 | } |
677 | EXPORT_SYMBOL(__bug); | |
678 | ||
679 | void __readwrite_bug(const char *fn) | |
680 | { | |
681 | printk("%s called, but not implemented\n", fn); | |
682 | BUG(); | |
683 | } | |
684 | EXPORT_SYMBOL(__readwrite_bug); | |
685 | ||
686 | void __pte_error(const char *file, int line, unsigned long val) | |
687 | { | |
688 | printk("%s:%d: bad pte %08lx.\n", file, line, val); | |
689 | } | |
690 | ||
691 | void __pmd_error(const char *file, int line, unsigned long val) | |
692 | { | |
693 | printk("%s:%d: bad pmd %08lx.\n", file, line, val); | |
694 | } | |
695 | ||
696 | void __pgd_error(const char *file, int line, unsigned long val) | |
697 | { | |
698 | printk("%s:%d: bad pgd %08lx.\n", file, line, val); | |
699 | } | |
700 | ||
701 | asmlinkage void __div0(void) | |
702 | { | |
703 | printk("Division by zero in kernel.\n"); | |
704 | dump_stack(); | |
705 | } | |
706 | EXPORT_SYMBOL(__div0); | |
707 | ||
708 | void abort(void) | |
709 | { | |
710 | BUG(); | |
711 | ||
712 | /* if that doesn't kill us, halt */ | |
713 | panic("Oops failed to kill thread"); | |
714 | } | |
715 | EXPORT_SYMBOL(abort); | |
716 | ||
717 | void __init trap_init(void) | |
5cbad0eb JW |
718 | { |
719 | return; | |
720 | } | |
721 | ||
722 | void __init early_trap_init(void) | |
1da177e4 | 723 | { |
c760fc19 | 724 | unsigned long vectors = CONFIG_VECTORS_BASE; |
7933523d RK |
725 | extern char __stubs_start[], __stubs_end[]; |
726 | extern char __vectors_start[], __vectors_end[]; | |
2d2669b6 NP |
727 | extern char __kuser_helper_start[], __kuser_helper_end[]; |
728 | int kuser_sz = __kuser_helper_end - __kuser_helper_start; | |
1da177e4 | 729 | |
7933523d | 730 | /* |
2d2669b6 NP |
731 | * Copy the vectors, stubs and kuser helpers (in entry-armv.S) |
732 | * into the vector page, mapped at 0xffff0000, and ensure these | |
733 | * are visible to the instruction stream. | |
7933523d | 734 | */ |
c760fc19 HC |
735 | memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start); |
736 | memcpy((void *)vectors + 0x200, __stubs_start, __stubs_end - __stubs_start); | |
737 | memcpy((void *)vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz); | |
e00d349e RK |
738 | |
739 | /* | |
740 | * Copy signal return handlers into the vector page, and | |
741 | * set sigreturn to be a pointer to these. | |
742 | */ | |
743 | memcpy((void *)KERN_SIGRETURN_CODE, sigreturn_codes, | |
744 | sizeof(sigreturn_codes)); | |
745 | ||
c760fc19 | 746 | flush_icache_range(vectors, vectors + PAGE_SIZE); |
1da177e4 LT |
747 | modify_domain(DOMAIN_USER, DOMAIN_CLIENT); |
748 | } |