]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/arch/arm/kernel/traps.c | |
3 | * | |
ab72b007 | 4 | * Copyright (C) 1995-2009 Russell King |
1da177e4 LT |
5 | * Fragments that appear the same as linux/arch/i386/kernel/traps.c (C) Linus Torvalds |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | * | |
11 | * 'traps.c' handles hardware exceptions after we have saved some state in | |
12 | * 'linux/arch/arm/lib/traps.S'. Mostly a debugging aid, but will probably | |
13 | * kill the offending process. | |
14 | */ | |
1da177e4 | 15 | #include <linux/signal.h> |
1da177e4 | 16 | #include <linux/personality.h> |
1da177e4 | 17 | #include <linux/kallsyms.h> |
a9221de6 RK |
18 | #include <linux/spinlock.h> |
19 | #include <linux/uaccess.h> | |
67306da6 | 20 | #include <linux/hardirq.h> |
a9221de6 RK |
21 | #include <linux/kdebug.h> |
22 | #include <linux/module.h> | |
23 | #include <linux/kexec.h> | |
24 | #include <linux/delay.h> | |
1da177e4 | 25 | #include <linux/init.h> |
425fc47a | 26 | #include <linux/sched.h> |
1da177e4 LT |
27 | |
28 | #include <asm/atomic.h> | |
29 | #include <asm/cacheflush.h> | |
1da177e4 | 30 | #include <asm/system.h> |
1da177e4 LT |
31 | #include <asm/unistd.h> |
32 | #include <asm/traps.h> | |
bff595c1 | 33 | #include <asm/unwind.h> |
f159f4ed | 34 | #include <asm/tls.h> |
1da177e4 | 35 | |
e00d349e | 36 | #include "signal.h" |
1da177e4 | 37 | |
1da177e4 LT |
38 | static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" }; |
39 | ||
247055aa CM |
40 | void *vectors_page; |
41 | ||
1da177e4 LT |
42 | #ifdef CONFIG_DEBUG_USER |
43 | unsigned int user_debug; | |
44 | ||
45 | static int __init user_debug_setup(char *str) | |
46 | { | |
47 | get_option(&str, &user_debug); | |
48 | return 1; | |
49 | } | |
50 | __setup("user_debug=", user_debug_setup); | |
51 | #endif | |
52 | ||
e40c2ec6 | 53 | static void dump_mem(const char *, const char *, unsigned long, unsigned long); |
7ab3f8d5 | 54 | |
7ab3f8d5 | 55 | void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame) |
1da177e4 LT |
56 | { |
57 | #ifdef CONFIG_KALLSYMS | |
69448c2a | 58 | printk("[<%08lx>] (%pS) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from); |
1da177e4 LT |
59 | #else |
60 | printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from); | |
61 | #endif | |
7ab3f8d5 RK |
62 | |
63 | if (in_exception_text(where)) | |
e40c2ec6 | 64 | dump_mem("", "Exception stack", frame + 4, frame + 4 + sizeof(struct pt_regs)); |
1da177e4 LT |
65 | } |
66 | ||
bff595c1 | 67 | #ifndef CONFIG_ARM_UNWIND |
1da177e4 LT |
68 | /* |
69 | * Stack pointers should always be within the kernels view of | |
70 | * physical memory. If it is not there, then we can't dump | |
71 | * out any information relating to the stack. | |
72 | */ | |
73 | static int verify_stack(unsigned long sp) | |
74 | { | |
09d9bae0 RK |
75 | if (sp < PAGE_OFFSET || |
76 | (sp > (unsigned long)high_memory && high_memory != NULL)) | |
1da177e4 LT |
77 | return -EFAULT; |
78 | ||
79 | return 0; | |
80 | } | |
bff595c1 | 81 | #endif |
1da177e4 LT |
82 | |
83 | /* | |
84 | * Dump out the contents of some memory nicely... | |
85 | */ | |
e40c2ec6 RK |
86 | static void dump_mem(const char *lvl, const char *str, unsigned long bottom, |
87 | unsigned long top) | |
1da177e4 | 88 | { |
d191fe09 | 89 | unsigned long first; |
1da177e4 LT |
90 | mm_segment_t fs; |
91 | int i; | |
92 | ||
93 | /* | |
94 | * We need to switch to kernel mode so that we can use __get_user | |
95 | * to safely read from kernel space. Note that we now dump the | |
96 | * code first, just in case the backtrace kills us. | |
97 | */ | |
98 | fs = get_fs(); | |
99 | set_fs(KERNEL_DS); | |
100 | ||
e40c2ec6 | 101 | printk("%s%s(0x%08lx to 0x%08lx)\n", lvl, str, bottom, top); |
1da177e4 | 102 | |
d191fe09 RK |
103 | for (first = bottom & ~31; first < top; first += 32) { |
104 | unsigned long p; | |
105 | char str[sizeof(" 12345678") * 8 + 1]; | |
1da177e4 | 106 | |
d191fe09 RK |
107 | memset(str, ' ', sizeof(str)); |
108 | str[sizeof(str) - 1] = '\0'; | |
1da177e4 | 109 | |
d191fe09 RK |
110 | for (p = first, i = 0; i < 8 && p < top; i++, p += 4) { |
111 | if (p >= bottom && p < top) { | |
112 | unsigned long val; | |
113 | if (__get_user(val, (unsigned long *)p) == 0) | |
114 | sprintf(str + i * 9, " %08lx", val); | |
115 | else | |
116 | sprintf(str + i * 9, " ????????"); | |
1da177e4 LT |
117 | } |
118 | } | |
e40c2ec6 | 119 | printk("%s%04lx:%s\n", lvl, first & 0xffff, str); |
1da177e4 LT |
120 | } |
121 | ||
122 | set_fs(fs); | |
123 | } | |
124 | ||
e40c2ec6 | 125 | static void dump_instr(const char *lvl, struct pt_regs *regs) |
1da177e4 LT |
126 | { |
127 | unsigned long addr = instruction_pointer(regs); | |
128 | const int thumb = thumb_mode(regs); | |
129 | const int width = thumb ? 4 : 8; | |
130 | mm_segment_t fs; | |
d191fe09 | 131 | char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str; |
1da177e4 LT |
132 | int i; |
133 | ||
134 | /* | |
135 | * We need to switch to kernel mode so that we can use __get_user | |
136 | * to safely read from kernel space. Note that we now dump the | |
137 | * code first, just in case the backtrace kills us. | |
138 | */ | |
139 | fs = get_fs(); | |
140 | set_fs(KERNEL_DS); | |
141 | ||
1da177e4 LT |
142 | for (i = -4; i < 1; i++) { |
143 | unsigned int val, bad; | |
144 | ||
145 | if (thumb) | |
146 | bad = __get_user(val, &((u16 *)addr)[i]); | |
147 | else | |
148 | bad = __get_user(val, &((u32 *)addr)[i]); | |
149 | ||
150 | if (!bad) | |
d191fe09 RK |
151 | p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ", |
152 | width, val); | |
1da177e4 | 153 | else { |
d191fe09 | 154 | p += sprintf(p, "bad PC value"); |
1da177e4 LT |
155 | break; |
156 | } | |
157 | } | |
e40c2ec6 | 158 | printk("%sCode: %s\n", lvl, str); |
1da177e4 LT |
159 | |
160 | set_fs(fs); | |
161 | } | |
162 | ||
bff595c1 CM |
163 | #ifdef CONFIG_ARM_UNWIND |
164 | static inline void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) | |
165 | { | |
166 | unwind_backtrace(regs, tsk); | |
167 | } | |
168 | #else | |
1da177e4 LT |
169 | static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) |
170 | { | |
67a94c23 | 171 | unsigned int fp, mode; |
1da177e4 LT |
172 | int ok = 1; |
173 | ||
174 | printk("Backtrace: "); | |
67a94c23 CM |
175 | |
176 | if (!tsk) | |
177 | tsk = current; | |
178 | ||
179 | if (regs) { | |
180 | fp = regs->ARM_fp; | |
181 | mode = processor_mode(regs); | |
182 | } else if (tsk != current) { | |
183 | fp = thread_saved_fp(tsk); | |
184 | mode = 0x10; | |
185 | } else { | |
186 | asm("mov %0, fp" : "=r" (fp) : : "cc"); | |
187 | mode = 0x10; | |
188 | } | |
189 | ||
1da177e4 LT |
190 | if (!fp) { |
191 | printk("no frame pointer"); | |
192 | ok = 0; | |
193 | } else if (verify_stack(fp)) { | |
194 | printk("invalid frame pointer 0x%08x", fp); | |
195 | ok = 0; | |
55205823 | 196 | } else if (fp < (unsigned long)end_of_stack(tsk)) |
1da177e4 LT |
197 | printk("frame pointer underflow"); |
198 | printk("\n"); | |
199 | ||
200 | if (ok) | |
67a94c23 | 201 | c_backtrace(fp, mode); |
1da177e4 | 202 | } |
bff595c1 | 203 | #endif |
1da177e4 LT |
204 | |
205 | void dump_stack(void) | |
206 | { | |
67a94c23 | 207 | dump_backtrace(NULL, NULL); |
1da177e4 LT |
208 | } |
209 | ||
210 | EXPORT_SYMBOL(dump_stack); | |
211 | ||
212 | void show_stack(struct task_struct *tsk, unsigned long *sp) | |
213 | { | |
67a94c23 | 214 | dump_backtrace(NULL, tsk); |
1da177e4 LT |
215 | barrier(); |
216 | } | |
217 | ||
d9202429 RK |
218 | #ifdef CONFIG_PREEMPT |
219 | #define S_PREEMPT " PREEMPT" | |
220 | #else | |
221 | #define S_PREEMPT "" | |
222 | #endif | |
223 | #ifdef CONFIG_SMP | |
224 | #define S_SMP " SMP" | |
225 | #else | |
226 | #define S_SMP "" | |
227 | #endif | |
228 | ||
a9221de6 | 229 | static int __die(const char *str, int err, struct thread_info *thread, struct pt_regs *regs) |
1da177e4 | 230 | { |
d362979a | 231 | struct task_struct *tsk = thread->task; |
1da177e4 | 232 | static int die_counter; |
a9221de6 | 233 | int ret; |
1da177e4 | 234 | |
e40c2ec6 | 235 | printk(KERN_EMERG "Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n", |
d9202429 | 236 | str, err, ++die_counter); |
a9221de6 RK |
237 | |
238 | /* trap and error numbers are mostly meaningless on ARM */ | |
239 | ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, SIGSEGV); | |
240 | if (ret == NOTIFY_STOP) | |
241 | return ret; | |
242 | ||
1da177e4 | 243 | print_modules(); |
652a12ef | 244 | __show_regs(regs); |
e40c2ec6 RK |
245 | printk(KERN_EMERG "Process %.*s (pid: %d, stack limit = 0x%p)\n", |
246 | TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1); | |
1da177e4 LT |
247 | |
248 | if (!user_mode(regs) || in_interrupt()) { | |
e40c2ec6 | 249 | dump_mem(KERN_EMERG, "Stack: ", regs->ARM_sp, |
32d39a93 | 250 | THREAD_SIZE + (unsigned long)task_stack_page(tsk)); |
1da177e4 | 251 | dump_backtrace(regs, tsk); |
e40c2ec6 | 252 | dump_instr(KERN_EMERG, regs); |
1da177e4 | 253 | } |
a9221de6 RK |
254 | |
255 | return ret; | |
d362979a | 256 | } |
1da177e4 | 257 | |
2bbd7e9b | 258 | static DEFINE_SPINLOCK(die_lock); |
d362979a RK |
259 | |
260 | /* | |
261 | * This function is protected against re-entrancy. | |
262 | */ | |
a9221de6 | 263 | void die(const char *str, struct pt_regs *regs, int err) |
d362979a RK |
264 | { |
265 | struct thread_info *thread = current_thread_info(); | |
a9221de6 | 266 | int ret; |
d362979a | 267 | |
d9202429 RK |
268 | oops_enter(); |
269 | ||
d362979a | 270 | spin_lock_irq(&die_lock); |
03a6e5bd | 271 | console_verbose(); |
d362979a | 272 | bust_spinlocks(1); |
a9221de6 RK |
273 | ret = __die(str, err, thread, regs); |
274 | ||
275 | if (regs && kexec_should_crash(thread->task)) | |
276 | crash_kexec(regs); | |
277 | ||
1da177e4 | 278 | bust_spinlocks(0); |
bcdcd8e7 | 279 | add_taint(TAINT_DIE); |
1da177e4 | 280 | spin_unlock_irq(&die_lock); |
03a6e5bd | 281 | oops_exit(); |
31867499 | 282 | |
d9202429 RK |
283 | if (in_interrupt()) |
284 | panic("Fatal exception in interrupt"); | |
cea6a4ba | 285 | if (panic_on_oops) |
012c437d | 286 | panic("Fatal exception"); |
a9221de6 RK |
287 | if (ret != NOTIFY_STOP) |
288 | do_exit(SIGSEGV); | |
1da177e4 LT |
289 | } |
290 | ||
1eeb66a1 CH |
291 | void arm_notify_die(const char *str, struct pt_regs *regs, |
292 | struct siginfo *info, unsigned long err, unsigned long trap) | |
1da177e4 LT |
293 | { |
294 | if (user_mode(regs)) { | |
295 | current->thread.error_code = err; | |
296 | current->thread.trap_no = trap; | |
297 | ||
298 | force_sig_info(info->si_signo, info, current); | |
299 | } else { | |
300 | die(str, regs, err); | |
301 | } | |
302 | } | |
303 | ||
304 | static LIST_HEAD(undef_hook); | |
305 | static DEFINE_SPINLOCK(undef_lock); | |
306 | ||
307 | void register_undef_hook(struct undef_hook *hook) | |
308 | { | |
109d89ca RK |
309 | unsigned long flags; |
310 | ||
311 | spin_lock_irqsave(&undef_lock, flags); | |
1da177e4 | 312 | list_add(&hook->node, &undef_hook); |
109d89ca | 313 | spin_unlock_irqrestore(&undef_lock, flags); |
1da177e4 LT |
314 | } |
315 | ||
316 | void unregister_undef_hook(struct undef_hook *hook) | |
317 | { | |
109d89ca RK |
318 | unsigned long flags; |
319 | ||
320 | spin_lock_irqsave(&undef_lock, flags); | |
1da177e4 | 321 | list_del(&hook->node); |
109d89ca | 322 | spin_unlock_irqrestore(&undef_lock, flags); |
1da177e4 LT |
323 | } |
324 | ||
b03a5b75 RK |
325 | static int call_undef_hook(struct pt_regs *regs, unsigned int instr) |
326 | { | |
327 | struct undef_hook *hook; | |
328 | unsigned long flags; | |
329 | int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL; | |
330 | ||
331 | spin_lock_irqsave(&undef_lock, flags); | |
332 | list_for_each_entry(hook, &undef_hook, node) | |
333 | if ((instr & hook->instr_mask) == hook->instr_val && | |
334 | (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val) | |
335 | fn = hook->fn; | |
336 | spin_unlock_irqrestore(&undef_lock, flags); | |
337 | ||
338 | return fn ? fn(regs, instr) : 1; | |
339 | } | |
340 | ||
7ab3f8d5 | 341 | asmlinkage void __exception do_undefinstr(struct pt_regs *regs) |
1da177e4 LT |
342 | { |
343 | unsigned int correction = thumb_mode(regs) ? 2 : 4; | |
344 | unsigned int instr; | |
1da177e4 LT |
345 | siginfo_t info; |
346 | void __user *pc; | |
347 | ||
348 | /* | |
349 | * According to the ARM ARM, PC is 2 or 4 bytes ahead, | |
350 | * depending whether we're in Thumb mode or not. | |
351 | * Correct this offset. | |
352 | */ | |
353 | regs->ARM_pc -= correction; | |
354 | ||
355 | pc = (void __user *)instruction_pointer(regs); | |
dfc544c7 DW |
356 | |
357 | if (processor_mode(regs) == SVC_MODE) { | |
358 | instr = *(u32 *) pc; | |
359 | } else if (thumb_mode(regs)) { | |
1da177e4 LT |
360 | get_user(instr, (u16 __user *)pc); |
361 | } else { | |
362 | get_user(instr, (u32 __user *)pc); | |
363 | } | |
364 | ||
b03a5b75 RK |
365 | if (call_undef_hook(regs, instr) == 0) |
366 | return; | |
1da177e4 LT |
367 | |
368 | #ifdef CONFIG_DEBUG_USER | |
369 | if (user_debug & UDBG_UNDEFINED) { | |
370 | printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n", | |
19c5870c | 371 | current->comm, task_pid_nr(current), pc); |
e40c2ec6 | 372 | dump_instr(KERN_INFO, regs); |
1da177e4 LT |
373 | } |
374 | #endif | |
375 | ||
376 | info.si_signo = SIGILL; | |
377 | info.si_errno = 0; | |
378 | info.si_code = ILL_ILLOPC; | |
379 | info.si_addr = pc; | |
380 | ||
1eeb66a1 | 381 | arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6); |
1da177e4 LT |
382 | } |
383 | ||
384 | asmlinkage void do_unexp_fiq (struct pt_regs *regs) | |
385 | { | |
1da177e4 LT |
386 | printk("Hmm. Unexpected FIQ received, but trying to continue\n"); |
387 | printk("You may have a hardware problem...\n"); | |
1da177e4 LT |
388 | } |
389 | ||
390 | /* | |
391 | * bad_mode handles the impossible case in the vectors. If you see one of | |
392 | * these, then it's extremely serious, and could mean you have buggy hardware. | |
393 | * It never returns, and never tries to sync. We hope that we can at least | |
394 | * dump out some state information... | |
395 | */ | |
ae0a846e | 396 | asmlinkage void bad_mode(struct pt_regs *regs, int reason) |
1da177e4 LT |
397 | { |
398 | console_verbose(); | |
399 | ||
ae0a846e | 400 | printk(KERN_CRIT "Bad mode in %s handler detected\n", handler[reason]); |
1da177e4 LT |
401 | |
402 | die("Oops - bad mode", regs, 0); | |
403 | local_irq_disable(); | |
404 | panic("bad mode"); | |
405 | } | |
406 | ||
407 | static int bad_syscall(int n, struct pt_regs *regs) | |
408 | { | |
409 | struct thread_info *thread = current_thread_info(); | |
410 | siginfo_t info; | |
411 | ||
88b9ef45 | 412 | if ((current->personality & PER_MASK) != PER_LINUX && |
a999cb04 | 413 | thread->exec_domain->handler) { |
1da177e4 LT |
414 | thread->exec_domain->handler(n, regs); |
415 | return regs->ARM_r0; | |
416 | } | |
417 | ||
418 | #ifdef CONFIG_DEBUG_USER | |
419 | if (user_debug & UDBG_SYSCALL) { | |
420 | printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n", | |
19c5870c | 421 | task_pid_nr(current), current->comm, n); |
e40c2ec6 | 422 | dump_instr(KERN_ERR, regs); |
1da177e4 LT |
423 | } |
424 | #endif | |
425 | ||
426 | info.si_signo = SIGILL; | |
427 | info.si_errno = 0; | |
428 | info.si_code = ILL_ILLTRP; | |
429 | info.si_addr = (void __user *)instruction_pointer(regs) - | |
430 | (thumb_mode(regs) ? 2 : 4); | |
431 | ||
1eeb66a1 | 432 | arm_notify_die("Oops - bad syscall", regs, &info, n, 0); |
1da177e4 LT |
433 | |
434 | return regs->ARM_r0; | |
435 | } | |
436 | ||
437 | static inline void | |
438 | do_cache_op(unsigned long start, unsigned long end, int flags) | |
439 | { | |
aa45ee8f | 440 | struct mm_struct *mm = current->active_mm; |
1da177e4 LT |
441 | struct vm_area_struct *vma; |
442 | ||
443 | if (end < start || flags) | |
444 | return; | |
445 | ||
aa45ee8f RK |
446 | down_read(&mm->mmap_sem); |
447 | vma = find_vma(mm, start); | |
1da177e4 LT |
448 | if (vma && vma->vm_start < end) { |
449 | if (start < vma->vm_start) | |
450 | start = vma->vm_start; | |
451 | if (end > vma->vm_end) | |
452 | end = vma->vm_end; | |
453 | ||
454 | flush_cache_user_range(vma, start, end); | |
455 | } | |
aa45ee8f | 456 | up_read(&mm->mmap_sem); |
1da177e4 LT |
457 | } |
458 | ||
459 | /* | |
460 | * Handle all unrecognised system calls. | |
461 | * 0x9f0000 - 0x9fffff are some more esoteric system calls | |
462 | */ | |
463 | #define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE) | |
464 | asmlinkage int arm_syscall(int no, struct pt_regs *regs) | |
465 | { | |
466 | struct thread_info *thread = current_thread_info(); | |
467 | siginfo_t info; | |
468 | ||
3f2829a3 | 469 | if ((no >> 16) != (__ARM_NR_BASE>> 16)) |
1da177e4 LT |
470 | return bad_syscall(no, regs); |
471 | ||
472 | switch (no & 0xffff) { | |
473 | case 0: /* branch through 0 */ | |
474 | info.si_signo = SIGSEGV; | |
475 | info.si_errno = 0; | |
476 | info.si_code = SEGV_MAPERR; | |
477 | info.si_addr = NULL; | |
478 | ||
1eeb66a1 | 479 | arm_notify_die("branch through zero", regs, &info, 0, 0); |
1da177e4 LT |
480 | return 0; |
481 | ||
482 | case NR(breakpoint): /* SWI BREAK_POINT */ | |
483 | regs->ARM_pc -= thumb_mode(regs) ? 2 : 4; | |
484 | ptrace_break(current, regs); | |
485 | return regs->ARM_r0; | |
486 | ||
487 | /* | |
488 | * Flush a region from virtual address 'r0' to virtual address 'r1' | |
489 | * _exclusive_. There is no alignment requirement on either address; | |
490 | * user space does not need to know the hardware cache layout. | |
491 | * | |
492 | * r2 contains flags. It should ALWAYS be passed as ZERO until it | |
493 | * is defined to be something else. For now we ignore it, but may | |
494 | * the fires of hell burn in your belly if you break this rule. ;) | |
495 | * | |
496 | * (at a later date, we may want to allow this call to not flush | |
497 | * various aspects of the cache. Passing '0' will guarantee that | |
498 | * everything necessary gets flushed to maintain consistency in | |
499 | * the specified region). | |
500 | */ | |
501 | case NR(cacheflush): | |
502 | do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2); | |
503 | return 0; | |
504 | ||
505 | case NR(usr26): | |
506 | if (!(elf_hwcap & HWCAP_26BIT)) | |
507 | break; | |
508 | regs->ARM_cpsr &= ~MODE32_BIT; | |
509 | return regs->ARM_r0; | |
510 | ||
511 | case NR(usr32): | |
512 | if (!(elf_hwcap & HWCAP_26BIT)) | |
513 | break; | |
514 | regs->ARM_cpsr |= MODE32_BIT; | |
515 | return regs->ARM_r0; | |
516 | ||
517 | case NR(set_tls): | |
518 | thread->tp_value = regs->ARM_r0; | |
f159f4ed TL |
519 | if (tls_emu) |
520 | return 0; | |
521 | if (has_tls_reg) { | |
522 | asm ("mcr p15, 0, %0, c13, c0, 3" | |
523 | : : "r" (regs->ARM_r0)); | |
524 | } else { | |
525 | /* | |
526 | * User space must never try to access this directly. | |
527 | * Expect your app to break eventually if you do so. | |
528 | * The user helper at 0xffff0fe0 must be used instead. | |
529 | * (see entry-armv.S for details) | |
530 | */ | |
531 | *((unsigned int *)0xffff0ff0) = regs->ARM_r0; | |
532 | } | |
1da177e4 LT |
533 | return 0; |
534 | ||
dcef1f63 NP |
535 | #ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG |
536 | /* | |
537 | * Atomically store r1 in *r2 if *r2 is equal to r0 for user space. | |
538 | * Return zero in r0 if *MEM was changed or non-zero if no exchange | |
539 | * happened. Also set the user C flag accordingly. | |
540 | * If access permissions have to be fixed up then non-zero is | |
541 | * returned and the operation has to be re-attempted. | |
542 | * | |
543 | * *NOTE*: This is a ghost syscall private to the kernel. Only the | |
544 | * __kuser_cmpxchg code in entry-armv.S should be aware of its | |
545 | * existence. Don't ever use this from user code. | |
546 | */ | |
cc20d429 | 547 | case NR(cmpxchg): |
b49c0f24 | 548 | for (;;) { |
dcef1f63 NP |
549 | extern void do_DataAbort(unsigned long addr, unsigned int fsr, |
550 | struct pt_regs *regs); | |
551 | unsigned long val; | |
552 | unsigned long addr = regs->ARM_r2; | |
553 | struct mm_struct *mm = current->mm; | |
554 | pgd_t *pgd; pmd_t *pmd; pte_t *pte; | |
69b04754 | 555 | spinlock_t *ptl; |
dcef1f63 NP |
556 | |
557 | regs->ARM_cpsr &= ~PSR_C_BIT; | |
69b04754 | 558 | down_read(&mm->mmap_sem); |
dcef1f63 NP |
559 | pgd = pgd_offset(mm, addr); |
560 | if (!pgd_present(*pgd)) | |
561 | goto bad_access; | |
562 | pmd = pmd_offset(pgd, addr); | |
563 | if (!pmd_present(*pmd)) | |
564 | goto bad_access; | |
69b04754 | 565 | pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
2ce9804f | 566 | if (!pte_present(*pte) || !pte_dirty(*pte)) { |
69b04754 | 567 | pte_unmap_unlock(pte, ptl); |
dcef1f63 | 568 | goto bad_access; |
69b04754 | 569 | } |
dcef1f63 NP |
570 | val = *(unsigned long *)addr; |
571 | val -= regs->ARM_r0; | |
572 | if (val == 0) { | |
573 | *(unsigned long *)addr = regs->ARM_r1; | |
574 | regs->ARM_cpsr |= PSR_C_BIT; | |
575 | } | |
69b04754 HD |
576 | pte_unmap_unlock(pte, ptl); |
577 | up_read(&mm->mmap_sem); | |
dcef1f63 NP |
578 | return val; |
579 | ||
580 | bad_access: | |
69b04754 | 581 | up_read(&mm->mmap_sem); |
74f88494 | 582 | /* simulate a write access fault */ |
dcef1f63 | 583 | do_DataAbort(addr, 15 + (1 << 11), regs); |
dcef1f63 NP |
584 | } |
585 | #endif | |
586 | ||
1da177e4 LT |
587 | default: |
588 | /* Calls 9f00xx..9f07ff are defined to return -ENOSYS | |
589 | if not implemented, rather than raising SIGILL. This | |
590 | way the calling program can gracefully determine whether | |
591 | a feature is supported. */ | |
bfd2e29f | 592 | if ((no & 0xffff) <= 0x7ff) |
1da177e4 LT |
593 | return -ENOSYS; |
594 | break; | |
595 | } | |
596 | #ifdef CONFIG_DEBUG_USER | |
597 | /* | |
598 | * experience shows that these seem to indicate that | |
599 | * something catastrophic has happened | |
600 | */ | |
601 | if (user_debug & UDBG_SYSCALL) { | |
602 | printk("[%d] %s: arm syscall %d\n", | |
19c5870c | 603 | task_pid_nr(current), current->comm, no); |
e40c2ec6 | 604 | dump_instr("", regs); |
1da177e4 | 605 | if (user_mode(regs)) { |
652a12ef | 606 | __show_regs(regs); |
1da177e4 LT |
607 | c_backtrace(regs->ARM_fp, processor_mode(regs)); |
608 | } | |
609 | } | |
610 | #endif | |
611 | info.si_signo = SIGILL; | |
612 | info.si_errno = 0; | |
613 | info.si_code = ILL_ILLTRP; | |
614 | info.si_addr = (void __user *)instruction_pointer(regs) - | |
615 | (thumb_mode(regs) ? 2 : 4); | |
616 | ||
1eeb66a1 | 617 | arm_notify_die("Oops - bad syscall(2)", regs, &info, no, 0); |
1da177e4 LT |
618 | return 0; |
619 | } | |
620 | ||
4b0e07a5 | 621 | #ifdef CONFIG_TLS_REG_EMUL |
2d2669b6 NP |
622 | |
623 | /* | |
624 | * We might be running on an ARMv6+ processor which should have the TLS | |
4b0e07a5 NP |
625 | * register but for some reason we can't use it, or maybe an SMP system |
626 | * using a pre-ARMv6 processor (there are apparently a few prototypes like | |
627 | * that in existence) and therefore access to that register must be | |
628 | * emulated. | |
2d2669b6 NP |
629 | */ |
630 | ||
631 | static int get_tp_trap(struct pt_regs *regs, unsigned int instr) | |
632 | { | |
633 | int reg = (instr >> 12) & 15; | |
634 | if (reg == 15) | |
635 | return 1; | |
636 | regs->uregs[reg] = current_thread_info()->tp_value; | |
637 | regs->ARM_pc += 4; | |
638 | return 0; | |
639 | } | |
640 | ||
641 | static struct undef_hook arm_mrc_hook = { | |
642 | .instr_mask = 0x0fff0fff, | |
643 | .instr_val = 0x0e1d0f70, | |
644 | .cpsr_mask = PSR_T_BIT, | |
645 | .cpsr_val = 0, | |
646 | .fn = get_tp_trap, | |
647 | }; | |
648 | ||
649 | static int __init arm_mrc_hook_init(void) | |
650 | { | |
651 | register_undef_hook(&arm_mrc_hook); | |
652 | return 0; | |
653 | } | |
654 | ||
655 | late_initcall(arm_mrc_hook_init); | |
656 | ||
657 | #endif | |
658 | ||
1da177e4 LT |
659 | void __bad_xchg(volatile void *ptr, int size) |
660 | { | |
661 | printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n", | |
662 | __builtin_return_address(0), ptr, size); | |
663 | BUG(); | |
664 | } | |
665 | EXPORT_SYMBOL(__bad_xchg); | |
666 | ||
667 | /* | |
668 | * A data abort trap was taken, but we did not handle the instruction. | |
669 | * Try to abort the user program, or panic if it was the kernel. | |
670 | */ | |
671 | asmlinkage void | |
672 | baddataabort(int code, unsigned long instr, struct pt_regs *regs) | |
673 | { | |
674 | unsigned long addr = instruction_pointer(regs); | |
675 | siginfo_t info; | |
676 | ||
677 | #ifdef CONFIG_DEBUG_USER | |
678 | if (user_debug & UDBG_BADABORT) { | |
679 | printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n", | |
19c5870c | 680 | task_pid_nr(current), current->comm, code, instr); |
e40c2ec6 | 681 | dump_instr(KERN_ERR, regs); |
1da177e4 LT |
682 | show_pte(current->mm, addr); |
683 | } | |
684 | #endif | |
685 | ||
686 | info.si_signo = SIGILL; | |
687 | info.si_errno = 0; | |
688 | info.si_code = ILL_ILLOPC; | |
689 | info.si_addr = (void __user *)addr; | |
690 | ||
1eeb66a1 | 691 | arm_notify_die("unknown data abort code", regs, &info, instr, 0); |
1da177e4 LT |
692 | } |
693 | ||
7174d852 | 694 | void __attribute__((noreturn)) __bug(const char *file, int line) |
1da177e4 | 695 | { |
7174d852 | 696 | printk(KERN_CRIT"kernel BUG at %s:%d!\n", file, line); |
1da177e4 | 697 | *(int *)0 = 0; |
6a1ced59 CM |
698 | |
699 | /* Avoid "noreturn function does return" */ | |
700 | for (;;); | |
1da177e4 LT |
701 | } |
702 | EXPORT_SYMBOL(__bug); | |
703 | ||
704 | void __readwrite_bug(const char *fn) | |
705 | { | |
706 | printk("%s called, but not implemented\n", fn); | |
707 | BUG(); | |
708 | } | |
709 | EXPORT_SYMBOL(__readwrite_bug); | |
710 | ||
69529c0e | 711 | void __pte_error(const char *file, int line, pte_t pte) |
1da177e4 | 712 | { |
29a38193 | 713 | printk("%s:%d: bad pte %08llx.\n", file, line, (long long)pte_val(pte)); |
1da177e4 LT |
714 | } |
715 | ||
69529c0e | 716 | void __pmd_error(const char *file, int line, pmd_t pmd) |
1da177e4 | 717 | { |
29a38193 | 718 | printk("%s:%d: bad pmd %08llx.\n", file, line, (long long)pmd_val(pmd)); |
1da177e4 LT |
719 | } |
720 | ||
69529c0e | 721 | void __pgd_error(const char *file, int line, pgd_t pgd) |
1da177e4 | 722 | { |
29a38193 | 723 | printk("%s:%d: bad pgd %08llx.\n", file, line, (long long)pgd_val(pgd)); |
1da177e4 LT |
724 | } |
725 | ||
726 | asmlinkage void __div0(void) | |
727 | { | |
728 | printk("Division by zero in kernel.\n"); | |
729 | dump_stack(); | |
730 | } | |
731 | EXPORT_SYMBOL(__div0); | |
732 | ||
733 | void abort(void) | |
734 | { | |
735 | BUG(); | |
736 | ||
737 | /* if that doesn't kill us, halt */ | |
738 | panic("Oops failed to kill thread"); | |
739 | } | |
740 | EXPORT_SYMBOL(abort); | |
741 | ||
742 | void __init trap_init(void) | |
5cbad0eb JW |
743 | { |
744 | return; | |
745 | } | |
746 | ||
f159f4ed TL |
747 | static void __init kuser_get_tls_init(unsigned long vectors) |
748 | { | |
749 | /* | |
750 | * vectors + 0xfe0 = __kuser_get_tls | |
751 | * vectors + 0xfe8 = hardware TLS instruction at 0xffff0fe8 | |
752 | */ | |
753 | if (tls_emu || has_tls_reg) | |
754 | memcpy((void *)vectors + 0xfe0, (void *)vectors + 0xfe8, 4); | |
755 | } | |
756 | ||
5cbad0eb | 757 | void __init early_trap_init(void) |
1da177e4 | 758 | { |
247055aa | 759 | #if defined(CONFIG_CPU_USE_DOMAINS) |
c760fc19 | 760 | unsigned long vectors = CONFIG_VECTORS_BASE; |
247055aa CM |
761 | #else |
762 | unsigned long vectors = (unsigned long)vectors_page; | |
763 | #endif | |
7933523d RK |
764 | extern char __stubs_start[], __stubs_end[]; |
765 | extern char __vectors_start[], __vectors_end[]; | |
2d2669b6 NP |
766 | extern char __kuser_helper_start[], __kuser_helper_end[]; |
767 | int kuser_sz = __kuser_helper_end - __kuser_helper_start; | |
1da177e4 | 768 | |
7933523d | 769 | /* |
2d2669b6 NP |
770 | * Copy the vectors, stubs and kuser helpers (in entry-armv.S) |
771 | * into the vector page, mapped at 0xffff0000, and ensure these | |
772 | * are visible to the instruction stream. | |
7933523d | 773 | */ |
c760fc19 HC |
774 | memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start); |
775 | memcpy((void *)vectors + 0x200, __stubs_start, __stubs_end - __stubs_start); | |
776 | memcpy((void *)vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz); | |
e00d349e | 777 | |
f159f4ed TL |
778 | /* |
779 | * Do processor specific fixups for the kuser helpers | |
780 | */ | |
781 | kuser_get_tls_init(vectors); | |
782 | ||
e00d349e RK |
783 | /* |
784 | * Copy signal return handlers into the vector page, and | |
785 | * set sigreturn to be a pointer to these. | |
786 | */ | |
247055aa CM |
787 | memcpy((void *)(vectors + KERN_SIGRETURN_CODE - CONFIG_VECTORS_BASE), |
788 | sigreturn_codes, sizeof(sigreturn_codes)); | |
789 | memcpy((void *)(vectors + KERN_RESTART_CODE - CONFIG_VECTORS_BASE), | |
790 | syscall_restart_code, sizeof(syscall_restart_code)); | |
e00d349e | 791 | |
c760fc19 | 792 | flush_icache_range(vectors, vectors + PAGE_SIZE); |
1da177e4 LT |
793 | modify_domain(DOMAIN_USER, DOMAIN_CLIENT); |
794 | } |