Commit | Line | Data |
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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 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 | ||
e40c2ec6 | 48 | static void dump_mem(const char *, const char *, unsigned long, unsigned long); |
7ab3f8d5 | 49 | |
7ab3f8d5 | 50 | void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame) |
1da177e4 LT |
51 | { |
52 | #ifdef CONFIG_KALLSYMS | |
d191fe09 RK |
53 | char sym1[KSYM_SYMBOL_LEN], sym2[KSYM_SYMBOL_LEN]; |
54 | sprint_symbol(sym1, where); | |
55 | sprint_symbol(sym2, from); | |
56 | printk("[<%08lx>] (%s) from [<%08lx>] (%s)\n", where, sym1, from, sym2); | |
1da177e4 LT |
57 | #else |
58 | printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from); | |
59 | #endif | |
7ab3f8d5 RK |
60 | |
61 | if (in_exception_text(where)) | |
e40c2ec6 | 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 | */ | |
e40c2ec6 RK |
84 | static void dump_mem(const char *lvl, const char *str, unsigned long bottom, |
85 | unsigned long top) | |
1da177e4 | 86 | { |
d191fe09 | 87 | unsigned long first; |
1da177e4 LT |
88 | mm_segment_t fs; |
89 | int i; | |
90 | ||
91 | /* | |
92 | * We need to switch to kernel mode so that we can use __get_user | |
93 | * to safely read from kernel space. Note that we now dump the | |
94 | * code first, just in case the backtrace kills us. | |
95 | */ | |
96 | fs = get_fs(); | |
97 | set_fs(KERNEL_DS); | |
98 | ||
e40c2ec6 | 99 | printk("%s%s(0x%08lx to 0x%08lx)\n", lvl, str, bottom, top); |
1da177e4 | 100 | |
d191fe09 RK |
101 | for (first = bottom & ~31; first < top; first += 32) { |
102 | unsigned long p; | |
103 | char str[sizeof(" 12345678") * 8 + 1]; | |
1da177e4 | 104 | |
d191fe09 RK |
105 | memset(str, ' ', sizeof(str)); |
106 | str[sizeof(str) - 1] = '\0'; | |
1da177e4 | 107 | |
d191fe09 RK |
108 | for (p = first, i = 0; i < 8 && p < top; i++, p += 4) { |
109 | if (p >= bottom && p < top) { | |
110 | unsigned long val; | |
111 | if (__get_user(val, (unsigned long *)p) == 0) | |
112 | sprintf(str + i * 9, " %08lx", val); | |
113 | else | |
114 | sprintf(str + i * 9, " ????????"); | |
1da177e4 LT |
115 | } |
116 | } | |
e40c2ec6 | 117 | printk("%s%04lx:%s\n", lvl, first & 0xffff, str); |
1da177e4 LT |
118 | } |
119 | ||
120 | set_fs(fs); | |
121 | } | |
122 | ||
e40c2ec6 | 123 | static void dump_instr(const char *lvl, struct pt_regs *regs) |
1da177e4 LT |
124 | { |
125 | unsigned long addr = instruction_pointer(regs); | |
126 | const int thumb = thumb_mode(regs); | |
127 | const int width = thumb ? 4 : 8; | |
128 | mm_segment_t fs; | |
d191fe09 | 129 | char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str; |
1da177e4 LT |
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 | ||
1da177e4 LT |
140 | for (i = -4; i < 1; i++) { |
141 | unsigned int val, bad; | |
142 | ||
143 | if (thumb) | |
144 | bad = __get_user(val, &((u16 *)addr)[i]); | |
145 | else | |
146 | bad = __get_user(val, &((u32 *)addr)[i]); | |
147 | ||
148 | if (!bad) | |
d191fe09 RK |
149 | p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ", |
150 | width, val); | |
1da177e4 | 151 | else { |
d191fe09 | 152 | p += sprintf(p, "bad PC value"); |
1da177e4 LT |
153 | break; |
154 | } | |
155 | } | |
e40c2ec6 | 156 | printk("%sCode: %s\n", lvl, str); |
1da177e4 LT |
157 | |
158 | set_fs(fs); | |
159 | } | |
160 | ||
bff595c1 CM |
161 | #ifdef CONFIG_ARM_UNWIND |
162 | static inline void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) | |
163 | { | |
164 | unwind_backtrace(regs, tsk); | |
165 | } | |
166 | #else | |
1da177e4 LT |
167 | static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) |
168 | { | |
67a94c23 | 169 | unsigned int fp, mode; |
1da177e4 LT |
170 | int ok = 1; |
171 | ||
172 | printk("Backtrace: "); | |
67a94c23 CM |
173 | |
174 | if (!tsk) | |
175 | tsk = current; | |
176 | ||
177 | if (regs) { | |
178 | fp = regs->ARM_fp; | |
179 | mode = processor_mode(regs); | |
180 | } else if (tsk != current) { | |
181 | fp = thread_saved_fp(tsk); | |
182 | mode = 0x10; | |
183 | } else { | |
184 | asm("mov %0, fp" : "=r" (fp) : : "cc"); | |
185 | mode = 0x10; | |
186 | } | |
187 | ||
1da177e4 LT |
188 | if (!fp) { |
189 | printk("no frame pointer"); | |
190 | ok = 0; | |
191 | } else if (verify_stack(fp)) { | |
192 | printk("invalid frame pointer 0x%08x", fp); | |
193 | ok = 0; | |
55205823 | 194 | } else if (fp < (unsigned long)end_of_stack(tsk)) |
1da177e4 LT |
195 | printk("frame pointer underflow"); |
196 | printk("\n"); | |
197 | ||
198 | if (ok) | |
67a94c23 | 199 | c_backtrace(fp, mode); |
1da177e4 | 200 | } |
bff595c1 | 201 | #endif |
1da177e4 LT |
202 | |
203 | void dump_stack(void) | |
204 | { | |
67a94c23 | 205 | dump_backtrace(NULL, NULL); |
1da177e4 LT |
206 | } |
207 | ||
208 | EXPORT_SYMBOL(dump_stack); | |
209 | ||
210 | void show_stack(struct task_struct *tsk, unsigned long *sp) | |
211 | { | |
67a94c23 | 212 | dump_backtrace(NULL, tsk); |
1da177e4 LT |
213 | barrier(); |
214 | } | |
215 | ||
d9202429 RK |
216 | #ifdef CONFIG_PREEMPT |
217 | #define S_PREEMPT " PREEMPT" | |
218 | #else | |
219 | #define S_PREEMPT "" | |
220 | #endif | |
221 | #ifdef CONFIG_SMP | |
222 | #define S_SMP " SMP" | |
223 | #else | |
224 | #define S_SMP "" | |
225 | #endif | |
226 | ||
d362979a | 227 | static void __die(const char *str, int err, struct thread_info *thread, struct pt_regs *regs) |
1da177e4 | 228 | { |
d362979a | 229 | struct task_struct *tsk = thread->task; |
1da177e4 LT |
230 | static int die_counter; |
231 | ||
e40c2ec6 | 232 | printk(KERN_EMERG "Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n", |
d9202429 | 233 | str, err, ++die_counter); |
03a6e5bd | 234 | sysfs_printk_last_file(); |
1da177e4 | 235 | print_modules(); |
652a12ef | 236 | __show_regs(regs); |
e40c2ec6 RK |
237 | printk(KERN_EMERG "Process %.*s (pid: %d, stack limit = 0x%p)\n", |
238 | TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1); | |
1da177e4 LT |
239 | |
240 | if (!user_mode(regs) || in_interrupt()) { | |
e40c2ec6 | 241 | dump_mem(KERN_EMERG, "Stack: ", regs->ARM_sp, |
32d39a93 | 242 | THREAD_SIZE + (unsigned long)task_stack_page(tsk)); |
1da177e4 | 243 | dump_backtrace(regs, tsk); |
e40c2ec6 | 244 | dump_instr(KERN_EMERG, regs); |
1da177e4 | 245 | } |
d362979a | 246 | } |
1da177e4 | 247 | |
d362979a RK |
248 | DEFINE_SPINLOCK(die_lock); |
249 | ||
250 | /* | |
251 | * This function is protected against re-entrancy. | |
252 | */ | |
253 | NORET_TYPE void die(const char *str, struct pt_regs *regs, int err) | |
254 | { | |
255 | struct thread_info *thread = current_thread_info(); | |
256 | ||
d9202429 RK |
257 | oops_enter(); |
258 | ||
d362979a | 259 | spin_lock_irq(&die_lock); |
03a6e5bd | 260 | console_verbose(); |
d362979a RK |
261 | bust_spinlocks(1); |
262 | __die(str, err, thread, regs); | |
1da177e4 | 263 | bust_spinlocks(0); |
bcdcd8e7 | 264 | add_taint(TAINT_DIE); |
1da177e4 | 265 | spin_unlock_irq(&die_lock); |
03a6e5bd | 266 | oops_exit(); |
31867499 | 267 | |
d9202429 RK |
268 | if (in_interrupt()) |
269 | panic("Fatal exception in interrupt"); | |
270 | ||
cea6a4ba | 271 | if (panic_on_oops) |
012c437d | 272 | panic("Fatal exception"); |
31867499 | 273 | |
1da177e4 LT |
274 | do_exit(SIGSEGV); |
275 | } | |
276 | ||
1eeb66a1 CH |
277 | void arm_notify_die(const char *str, struct pt_regs *regs, |
278 | struct siginfo *info, unsigned long err, unsigned long trap) | |
1da177e4 LT |
279 | { |
280 | if (user_mode(regs)) { | |
281 | current->thread.error_code = err; | |
282 | current->thread.trap_no = trap; | |
283 | ||
284 | force_sig_info(info->si_signo, info, current); | |
285 | } else { | |
286 | die(str, regs, err); | |
287 | } | |
288 | } | |
289 | ||
290 | static LIST_HEAD(undef_hook); | |
291 | static DEFINE_SPINLOCK(undef_lock); | |
292 | ||
293 | void register_undef_hook(struct undef_hook *hook) | |
294 | { | |
109d89ca RK |
295 | unsigned long flags; |
296 | ||
297 | spin_lock_irqsave(&undef_lock, flags); | |
1da177e4 | 298 | list_add(&hook->node, &undef_hook); |
109d89ca | 299 | spin_unlock_irqrestore(&undef_lock, flags); |
1da177e4 LT |
300 | } |
301 | ||
302 | void unregister_undef_hook(struct undef_hook *hook) | |
303 | { | |
109d89ca RK |
304 | unsigned long flags; |
305 | ||
306 | spin_lock_irqsave(&undef_lock, flags); | |
1da177e4 | 307 | list_del(&hook->node); |
109d89ca | 308 | spin_unlock_irqrestore(&undef_lock, flags); |
1da177e4 LT |
309 | } |
310 | ||
b03a5b75 RK |
311 | static int call_undef_hook(struct pt_regs *regs, unsigned int instr) |
312 | { | |
313 | struct undef_hook *hook; | |
314 | unsigned long flags; | |
315 | int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL; | |
316 | ||
317 | spin_lock_irqsave(&undef_lock, flags); | |
318 | list_for_each_entry(hook, &undef_hook, node) | |
319 | if ((instr & hook->instr_mask) == hook->instr_val && | |
320 | (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val) | |
321 | fn = hook->fn; | |
322 | spin_unlock_irqrestore(&undef_lock, flags); | |
323 | ||
324 | return fn ? fn(regs, instr) : 1; | |
325 | } | |
326 | ||
7ab3f8d5 | 327 | asmlinkage void __exception do_undefinstr(struct pt_regs *regs) |
1da177e4 LT |
328 | { |
329 | unsigned int correction = thumb_mode(regs) ? 2 : 4; | |
330 | unsigned int instr; | |
1da177e4 LT |
331 | siginfo_t info; |
332 | void __user *pc; | |
333 | ||
334 | /* | |
335 | * According to the ARM ARM, PC is 2 or 4 bytes ahead, | |
336 | * depending whether we're in Thumb mode or not. | |
337 | * Correct this offset. | |
338 | */ | |
339 | regs->ARM_pc -= correction; | |
340 | ||
341 | pc = (void __user *)instruction_pointer(regs); | |
dfc544c7 DW |
342 | |
343 | if (processor_mode(regs) == SVC_MODE) { | |
344 | instr = *(u32 *) pc; | |
345 | } else if (thumb_mode(regs)) { | |
1da177e4 LT |
346 | get_user(instr, (u16 __user *)pc); |
347 | } else { | |
348 | get_user(instr, (u32 __user *)pc); | |
349 | } | |
350 | ||
b03a5b75 RK |
351 | if (call_undef_hook(regs, instr) == 0) |
352 | return; | |
1da177e4 LT |
353 | |
354 | #ifdef CONFIG_DEBUG_USER | |
355 | if (user_debug & UDBG_UNDEFINED) { | |
356 | printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n", | |
19c5870c | 357 | current->comm, task_pid_nr(current), pc); |
e40c2ec6 | 358 | dump_instr(KERN_INFO, regs); |
1da177e4 LT |
359 | } |
360 | #endif | |
361 | ||
362 | info.si_signo = SIGILL; | |
363 | info.si_errno = 0; | |
364 | info.si_code = ILL_ILLOPC; | |
365 | info.si_addr = pc; | |
366 | ||
1eeb66a1 | 367 | arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6); |
1da177e4 LT |
368 | } |
369 | ||
370 | asmlinkage void do_unexp_fiq (struct pt_regs *regs) | |
371 | { | |
1da177e4 LT |
372 | printk("Hmm. Unexpected FIQ received, but trying to continue\n"); |
373 | printk("You may have a hardware problem...\n"); | |
1da177e4 LT |
374 | } |
375 | ||
376 | /* | |
377 | * bad_mode handles the impossible case in the vectors. If you see one of | |
378 | * these, then it's extremely serious, and could mean you have buggy hardware. | |
379 | * It never returns, and never tries to sync. We hope that we can at least | |
380 | * dump out some state information... | |
381 | */ | |
ae0a846e | 382 | asmlinkage void bad_mode(struct pt_regs *regs, int reason) |
1da177e4 LT |
383 | { |
384 | console_verbose(); | |
385 | ||
ae0a846e | 386 | printk(KERN_CRIT "Bad mode in %s handler detected\n", handler[reason]); |
1da177e4 LT |
387 | |
388 | die("Oops - bad mode", regs, 0); | |
389 | local_irq_disable(); | |
390 | panic("bad mode"); | |
391 | } | |
392 | ||
393 | static int bad_syscall(int n, struct pt_regs *regs) | |
394 | { | |
395 | struct thread_info *thread = current_thread_info(); | |
396 | siginfo_t info; | |
397 | ||
a999cb04 NP |
398 | if (current->personality != PER_LINUX && |
399 | current->personality != PER_LINUX_32BIT && | |
400 | thread->exec_domain->handler) { | |
1da177e4 LT |
401 | thread->exec_domain->handler(n, regs); |
402 | return regs->ARM_r0; | |
403 | } | |
404 | ||
405 | #ifdef CONFIG_DEBUG_USER | |
406 | if (user_debug & UDBG_SYSCALL) { | |
407 | printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n", | |
19c5870c | 408 | task_pid_nr(current), current->comm, n); |
e40c2ec6 | 409 | dump_instr(KERN_ERR, regs); |
1da177e4 LT |
410 | } |
411 | #endif | |
412 | ||
413 | info.si_signo = SIGILL; | |
414 | info.si_errno = 0; | |
415 | info.si_code = ILL_ILLTRP; | |
416 | info.si_addr = (void __user *)instruction_pointer(regs) - | |
417 | (thumb_mode(regs) ? 2 : 4); | |
418 | ||
1eeb66a1 | 419 | arm_notify_die("Oops - bad syscall", regs, &info, n, 0); |
1da177e4 LT |
420 | |
421 | return regs->ARM_r0; | |
422 | } | |
423 | ||
424 | static inline void | |
425 | do_cache_op(unsigned long start, unsigned long end, int flags) | |
426 | { | |
aa45ee8f | 427 | struct mm_struct *mm = current->active_mm; |
1da177e4 LT |
428 | struct vm_area_struct *vma; |
429 | ||
430 | if (end < start || flags) | |
431 | return; | |
432 | ||
aa45ee8f RK |
433 | down_read(&mm->mmap_sem); |
434 | vma = find_vma(mm, start); | |
1da177e4 LT |
435 | if (vma && vma->vm_start < end) { |
436 | if (start < vma->vm_start) | |
437 | start = vma->vm_start; | |
438 | if (end > vma->vm_end) | |
439 | end = vma->vm_end; | |
440 | ||
441 | flush_cache_user_range(vma, start, end); | |
442 | } | |
aa45ee8f | 443 | up_read(&mm->mmap_sem); |
1da177e4 LT |
444 | } |
445 | ||
446 | /* | |
447 | * Handle all unrecognised system calls. | |
448 | * 0x9f0000 - 0x9fffff are some more esoteric system calls | |
449 | */ | |
450 | #define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE) | |
451 | asmlinkage int arm_syscall(int no, struct pt_regs *regs) | |
452 | { | |
453 | struct thread_info *thread = current_thread_info(); | |
454 | siginfo_t info; | |
455 | ||
3f2829a3 | 456 | if ((no >> 16) != (__ARM_NR_BASE>> 16)) |
1da177e4 LT |
457 | return bad_syscall(no, regs); |
458 | ||
459 | switch (no & 0xffff) { | |
460 | case 0: /* branch through 0 */ | |
461 | info.si_signo = SIGSEGV; | |
462 | info.si_errno = 0; | |
463 | info.si_code = SEGV_MAPERR; | |
464 | info.si_addr = NULL; | |
465 | ||
1eeb66a1 | 466 | arm_notify_die("branch through zero", regs, &info, 0, 0); |
1da177e4 LT |
467 | return 0; |
468 | ||
469 | case NR(breakpoint): /* SWI BREAK_POINT */ | |
470 | regs->ARM_pc -= thumb_mode(regs) ? 2 : 4; | |
471 | ptrace_break(current, regs); | |
472 | return regs->ARM_r0; | |
473 | ||
474 | /* | |
475 | * Flush a region from virtual address 'r0' to virtual address 'r1' | |
476 | * _exclusive_. There is no alignment requirement on either address; | |
477 | * user space does not need to know the hardware cache layout. | |
478 | * | |
479 | * r2 contains flags. It should ALWAYS be passed as ZERO until it | |
480 | * is defined to be something else. For now we ignore it, but may | |
481 | * the fires of hell burn in your belly if you break this rule. ;) | |
482 | * | |
483 | * (at a later date, we may want to allow this call to not flush | |
484 | * various aspects of the cache. Passing '0' will guarantee that | |
485 | * everything necessary gets flushed to maintain consistency in | |
486 | * the specified region). | |
487 | */ | |
488 | case NR(cacheflush): | |
489 | do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2); | |
490 | return 0; | |
491 | ||
492 | case NR(usr26): | |
493 | if (!(elf_hwcap & HWCAP_26BIT)) | |
494 | break; | |
495 | regs->ARM_cpsr &= ~MODE32_BIT; | |
496 | return regs->ARM_r0; | |
497 | ||
498 | case NR(usr32): | |
499 | if (!(elf_hwcap & HWCAP_26BIT)) | |
500 | break; | |
501 | regs->ARM_cpsr |= MODE32_BIT; | |
502 | return regs->ARM_r0; | |
503 | ||
504 | case NR(set_tls): | |
505 | thread->tp_value = regs->ARM_r0; | |
4b0e07a5 | 506 | #if defined(CONFIG_HAS_TLS_REG) |
2d2669b6 | 507 | asm ("mcr p15, 0, %0, c13, c0, 3" : : "r" (regs->ARM_r0) ); |
4b0e07a5 | 508 | #elif !defined(CONFIG_TLS_REG_EMUL) |
1da177e4 | 509 | /* |
2d2669b6 NP |
510 | * User space must never try to access this directly. |
511 | * Expect your app to break eventually if you do so. | |
512 | * The user helper at 0xffff0fe0 must be used instead. | |
513 | * (see entry-armv.S for details) | |
1da177e4 | 514 | */ |
2d2669b6 NP |
515 | *((unsigned int *)0xffff0ff0) = regs->ARM_r0; |
516 | #endif | |
1da177e4 LT |
517 | return 0; |
518 | ||
dcef1f63 NP |
519 | #ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG |
520 | /* | |
521 | * Atomically store r1 in *r2 if *r2 is equal to r0 for user space. | |
522 | * Return zero in r0 if *MEM was changed or non-zero if no exchange | |
523 | * happened. Also set the user C flag accordingly. | |
524 | * If access permissions have to be fixed up then non-zero is | |
525 | * returned and the operation has to be re-attempted. | |
526 | * | |
527 | * *NOTE*: This is a ghost syscall private to the kernel. Only the | |
528 | * __kuser_cmpxchg code in entry-armv.S should be aware of its | |
529 | * existence. Don't ever use this from user code. | |
530 | */ | |
531 | case 0xfff0: | |
b49c0f24 | 532 | for (;;) { |
dcef1f63 NP |
533 | extern void do_DataAbort(unsigned long addr, unsigned int fsr, |
534 | struct pt_regs *regs); | |
535 | unsigned long val; | |
536 | unsigned long addr = regs->ARM_r2; | |
537 | struct mm_struct *mm = current->mm; | |
538 | pgd_t *pgd; pmd_t *pmd; pte_t *pte; | |
69b04754 | 539 | spinlock_t *ptl; |
dcef1f63 NP |
540 | |
541 | regs->ARM_cpsr &= ~PSR_C_BIT; | |
69b04754 | 542 | down_read(&mm->mmap_sem); |
dcef1f63 NP |
543 | pgd = pgd_offset(mm, addr); |
544 | if (!pgd_present(*pgd)) | |
545 | goto bad_access; | |
546 | pmd = pmd_offset(pgd, addr); | |
547 | if (!pmd_present(*pmd)) | |
548 | goto bad_access; | |
69b04754 | 549 | pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
2ce9804f | 550 | if (!pte_present(*pte) || !pte_dirty(*pte)) { |
69b04754 | 551 | pte_unmap_unlock(pte, ptl); |
dcef1f63 | 552 | goto bad_access; |
69b04754 | 553 | } |
dcef1f63 NP |
554 | val = *(unsigned long *)addr; |
555 | val -= regs->ARM_r0; | |
556 | if (val == 0) { | |
557 | *(unsigned long *)addr = regs->ARM_r1; | |
558 | regs->ARM_cpsr |= PSR_C_BIT; | |
559 | } | |
69b04754 HD |
560 | pte_unmap_unlock(pte, ptl); |
561 | up_read(&mm->mmap_sem); | |
dcef1f63 NP |
562 | return val; |
563 | ||
564 | bad_access: | |
69b04754 | 565 | up_read(&mm->mmap_sem); |
74f88494 | 566 | /* simulate a write access fault */ |
dcef1f63 | 567 | do_DataAbort(addr, 15 + (1 << 11), regs); |
dcef1f63 NP |
568 | } |
569 | #endif | |
570 | ||
1da177e4 LT |
571 | default: |
572 | /* Calls 9f00xx..9f07ff are defined to return -ENOSYS | |
573 | if not implemented, rather than raising SIGILL. This | |
574 | way the calling program can gracefully determine whether | |
575 | a feature is supported. */ | |
576 | if (no <= 0x7ff) | |
577 | return -ENOSYS; | |
578 | break; | |
579 | } | |
580 | #ifdef CONFIG_DEBUG_USER | |
581 | /* | |
582 | * experience shows that these seem to indicate that | |
583 | * something catastrophic has happened | |
584 | */ | |
585 | if (user_debug & UDBG_SYSCALL) { | |
586 | printk("[%d] %s: arm syscall %d\n", | |
19c5870c | 587 | task_pid_nr(current), current->comm, no); |
e40c2ec6 | 588 | dump_instr("", regs); |
1da177e4 | 589 | if (user_mode(regs)) { |
652a12ef | 590 | __show_regs(regs); |
1da177e4 LT |
591 | c_backtrace(regs->ARM_fp, processor_mode(regs)); |
592 | } | |
593 | } | |
594 | #endif | |
595 | info.si_signo = SIGILL; | |
596 | info.si_errno = 0; | |
597 | info.si_code = ILL_ILLTRP; | |
598 | info.si_addr = (void __user *)instruction_pointer(regs) - | |
599 | (thumb_mode(regs) ? 2 : 4); | |
600 | ||
1eeb66a1 | 601 | arm_notify_die("Oops - bad syscall(2)", regs, &info, no, 0); |
1da177e4 LT |
602 | return 0; |
603 | } | |
604 | ||
4b0e07a5 | 605 | #ifdef CONFIG_TLS_REG_EMUL |
2d2669b6 NP |
606 | |
607 | /* | |
608 | * We might be running on an ARMv6+ processor which should have the TLS | |
4b0e07a5 NP |
609 | * register but for some reason we can't use it, or maybe an SMP system |
610 | * using a pre-ARMv6 processor (there are apparently a few prototypes like | |
611 | * that in existence) and therefore access to that register must be | |
612 | * emulated. | |
2d2669b6 NP |
613 | */ |
614 | ||
615 | static int get_tp_trap(struct pt_regs *regs, unsigned int instr) | |
616 | { | |
617 | int reg = (instr >> 12) & 15; | |
618 | if (reg == 15) | |
619 | return 1; | |
620 | regs->uregs[reg] = current_thread_info()->tp_value; | |
621 | regs->ARM_pc += 4; | |
622 | return 0; | |
623 | } | |
624 | ||
625 | static struct undef_hook arm_mrc_hook = { | |
626 | .instr_mask = 0x0fff0fff, | |
627 | .instr_val = 0x0e1d0f70, | |
628 | .cpsr_mask = PSR_T_BIT, | |
629 | .cpsr_val = 0, | |
630 | .fn = get_tp_trap, | |
631 | }; | |
632 | ||
633 | static int __init arm_mrc_hook_init(void) | |
634 | { | |
635 | register_undef_hook(&arm_mrc_hook); | |
636 | return 0; | |
637 | } | |
638 | ||
639 | late_initcall(arm_mrc_hook_init); | |
640 | ||
641 | #endif | |
642 | ||
1da177e4 LT |
643 | void __bad_xchg(volatile void *ptr, int size) |
644 | { | |
645 | printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n", | |
646 | __builtin_return_address(0), ptr, size); | |
647 | BUG(); | |
648 | } | |
649 | EXPORT_SYMBOL(__bad_xchg); | |
650 | ||
651 | /* | |
652 | * A data abort trap was taken, but we did not handle the instruction. | |
653 | * Try to abort the user program, or panic if it was the kernel. | |
654 | */ | |
655 | asmlinkage void | |
656 | baddataabort(int code, unsigned long instr, struct pt_regs *regs) | |
657 | { | |
658 | unsigned long addr = instruction_pointer(regs); | |
659 | siginfo_t info; | |
660 | ||
661 | #ifdef CONFIG_DEBUG_USER | |
662 | if (user_debug & UDBG_BADABORT) { | |
663 | printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n", | |
19c5870c | 664 | task_pid_nr(current), current->comm, code, instr); |
e40c2ec6 | 665 | dump_instr(KERN_ERR, regs); |
1da177e4 LT |
666 | show_pte(current->mm, addr); |
667 | } | |
668 | #endif | |
669 | ||
670 | info.si_signo = SIGILL; | |
671 | info.si_errno = 0; | |
672 | info.si_code = ILL_ILLOPC; | |
673 | info.si_addr = (void __user *)addr; | |
674 | ||
1eeb66a1 | 675 | arm_notify_die("unknown data abort code", regs, &info, instr, 0); |
1da177e4 LT |
676 | } |
677 | ||
7174d852 | 678 | void __attribute__((noreturn)) __bug(const char *file, int line) |
1da177e4 | 679 | { |
7174d852 | 680 | printk(KERN_CRIT"kernel BUG at %s:%d!\n", file, line); |
1da177e4 | 681 | *(int *)0 = 0; |
6a1ced59 CM |
682 | |
683 | /* Avoid "noreturn function does return" */ | |
684 | for (;;); | |
1da177e4 LT |
685 | } |
686 | EXPORT_SYMBOL(__bug); | |
687 | ||
688 | void __readwrite_bug(const char *fn) | |
689 | { | |
690 | printk("%s called, but not implemented\n", fn); | |
691 | BUG(); | |
692 | } | |
693 | EXPORT_SYMBOL(__readwrite_bug); | |
694 | ||
695 | void __pte_error(const char *file, int line, unsigned long val) | |
696 | { | |
697 | printk("%s:%d: bad pte %08lx.\n", file, line, val); | |
698 | } | |
699 | ||
700 | void __pmd_error(const char *file, int line, unsigned long val) | |
701 | { | |
702 | printk("%s:%d: bad pmd %08lx.\n", file, line, val); | |
703 | } | |
704 | ||
705 | void __pgd_error(const char *file, int line, unsigned long val) | |
706 | { | |
707 | printk("%s:%d: bad pgd %08lx.\n", file, line, val); | |
708 | } | |
709 | ||
710 | asmlinkage void __div0(void) | |
711 | { | |
712 | printk("Division by zero in kernel.\n"); | |
713 | dump_stack(); | |
714 | } | |
715 | EXPORT_SYMBOL(__div0); | |
716 | ||
717 | void abort(void) | |
718 | { | |
719 | BUG(); | |
720 | ||
721 | /* if that doesn't kill us, halt */ | |
722 | panic("Oops failed to kill thread"); | |
723 | } | |
724 | EXPORT_SYMBOL(abort); | |
725 | ||
726 | void __init trap_init(void) | |
5cbad0eb JW |
727 | { |
728 | return; | |
729 | } | |
730 | ||
731 | void __init early_trap_init(void) | |
1da177e4 | 732 | { |
c760fc19 | 733 | unsigned long vectors = CONFIG_VECTORS_BASE; |
7933523d RK |
734 | extern char __stubs_start[], __stubs_end[]; |
735 | extern char __vectors_start[], __vectors_end[]; | |
2d2669b6 NP |
736 | extern char __kuser_helper_start[], __kuser_helper_end[]; |
737 | int kuser_sz = __kuser_helper_end - __kuser_helper_start; | |
1da177e4 | 738 | |
7933523d | 739 | /* |
2d2669b6 NP |
740 | * Copy the vectors, stubs and kuser helpers (in entry-armv.S) |
741 | * into the vector page, mapped at 0xffff0000, and ensure these | |
742 | * are visible to the instruction stream. | |
7933523d | 743 | */ |
c760fc19 HC |
744 | memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start); |
745 | memcpy((void *)vectors + 0x200, __stubs_start, __stubs_end - __stubs_start); | |
746 | memcpy((void *)vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz); | |
e00d349e RK |
747 | |
748 | /* | |
749 | * Copy signal return handlers into the vector page, and | |
750 | * set sigreturn to be a pointer to these. | |
751 | */ | |
752 | memcpy((void *)KERN_SIGRETURN_CODE, sigreturn_codes, | |
753 | sizeof(sigreturn_codes)); | |
ab72b007 RK |
754 | memcpy((void *)KERN_RESTART_CODE, syscall_restart_code, |
755 | sizeof(syscall_restart_code)); | |
e00d349e | 756 | |
c760fc19 | 757 | flush_icache_range(vectors, vectors + PAGE_SIZE); |
1da177e4 LT |
758 | modify_domain(DOMAIN_USER, DOMAIN_CLIENT); |
759 | } |