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> | |
87e040b6 | 24 | #include <linux/bug.h> |
a9221de6 | 25 | #include <linux/delay.h> |
1da177e4 | 26 | #include <linux/init.h> |
425fc47a | 27 | #include <linux/sched.h> |
1da177e4 | 28 | |
60063497 | 29 | #include <linux/atomic.h> |
1da177e4 | 30 | #include <asm/cacheflush.h> |
5a567d78 | 31 | #include <asm/exception.h> |
1da177e4 LT |
32 | #include <asm/unistd.h> |
33 | #include <asm/traps.h> | |
bff595c1 | 34 | #include <asm/unwind.h> |
f159f4ed | 35 | #include <asm/tls.h> |
9f97da78 | 36 | #include <asm/system_misc.h> |
1da177e4 | 37 | |
e00d349e | 38 | #include "signal.h" |
1da177e4 | 39 | |
1da177e4 LT |
40 | static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" }; |
41 | ||
247055aa CM |
42 | void *vectors_page; |
43 | ||
1da177e4 LT |
44 | #ifdef CONFIG_DEBUG_USER |
45 | unsigned int user_debug; | |
46 | ||
47 | static int __init user_debug_setup(char *str) | |
48 | { | |
49 | get_option(&str, &user_debug); | |
50 | return 1; | |
51 | } | |
52 | __setup("user_debug=", user_debug_setup); | |
53 | #endif | |
54 | ||
e40c2ec6 | 55 | static void dump_mem(const char *, const char *, unsigned long, unsigned long); |
7ab3f8d5 | 56 | |
7ab3f8d5 | 57 | void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame) |
1da177e4 LT |
58 | { |
59 | #ifdef CONFIG_KALLSYMS | |
69448c2a | 60 | printk("[<%08lx>] (%pS) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from); |
1da177e4 LT |
61 | #else |
62 | printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from); | |
63 | #endif | |
7ab3f8d5 RK |
64 | |
65 | if (in_exception_text(where)) | |
e40c2ec6 | 66 | dump_mem("", "Exception stack", frame + 4, frame + 4 + sizeof(struct pt_regs)); |
1da177e4 LT |
67 | } |
68 | ||
bff595c1 | 69 | #ifndef CONFIG_ARM_UNWIND |
1da177e4 LT |
70 | /* |
71 | * Stack pointers should always be within the kernels view of | |
72 | * physical memory. If it is not there, then we can't dump | |
73 | * out any information relating to the stack. | |
74 | */ | |
75 | static int verify_stack(unsigned long sp) | |
76 | { | |
09d9bae0 RK |
77 | if (sp < PAGE_OFFSET || |
78 | (sp > (unsigned long)high_memory && high_memory != NULL)) | |
1da177e4 LT |
79 | return -EFAULT; |
80 | ||
81 | return 0; | |
82 | } | |
bff595c1 | 83 | #endif |
1da177e4 LT |
84 | |
85 | /* | |
86 | * Dump out the contents of some memory nicely... | |
87 | */ | |
e40c2ec6 RK |
88 | static void dump_mem(const char *lvl, const char *str, unsigned long bottom, |
89 | unsigned long top) | |
1da177e4 | 90 | { |
d191fe09 | 91 | unsigned long first; |
1da177e4 LT |
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 | ||
e40c2ec6 | 103 | printk("%s%s(0x%08lx to 0x%08lx)\n", lvl, str, bottom, top); |
1da177e4 | 104 | |
d191fe09 RK |
105 | for (first = bottom & ~31; first < top; first += 32) { |
106 | unsigned long p; | |
107 | char str[sizeof(" 12345678") * 8 + 1]; | |
1da177e4 | 108 | |
d191fe09 RK |
109 | memset(str, ' ', sizeof(str)); |
110 | str[sizeof(str) - 1] = '\0'; | |
1da177e4 | 111 | |
d191fe09 RK |
112 | for (p = first, i = 0; i < 8 && p < top; i++, p += 4) { |
113 | if (p >= bottom && p < top) { | |
114 | unsigned long val; | |
115 | if (__get_user(val, (unsigned long *)p) == 0) | |
116 | sprintf(str + i * 9, " %08lx", val); | |
117 | else | |
118 | sprintf(str + i * 9, " ????????"); | |
1da177e4 LT |
119 | } |
120 | } | |
e40c2ec6 | 121 | printk("%s%04lx:%s\n", lvl, first & 0xffff, str); |
1da177e4 LT |
122 | } |
123 | ||
124 | set_fs(fs); | |
125 | } | |
126 | ||
e40c2ec6 | 127 | static void dump_instr(const char *lvl, struct pt_regs *regs) |
1da177e4 LT |
128 | { |
129 | unsigned long addr = instruction_pointer(regs); | |
130 | const int thumb = thumb_mode(regs); | |
131 | const int width = thumb ? 4 : 8; | |
132 | mm_segment_t fs; | |
d191fe09 | 133 | char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str; |
1da177e4 LT |
134 | int i; |
135 | ||
136 | /* | |
137 | * We need to switch to kernel mode so that we can use __get_user | |
138 | * to safely read from kernel space. Note that we now dump the | |
139 | * code first, just in case the backtrace kills us. | |
140 | */ | |
141 | fs = get_fs(); | |
142 | set_fs(KERNEL_DS); | |
143 | ||
a9011580 | 144 | for (i = -4; i < 1 + !!thumb; i++) { |
1da177e4 LT |
145 | unsigned int val, bad; |
146 | ||
147 | if (thumb) | |
148 | bad = __get_user(val, &((u16 *)addr)[i]); | |
149 | else | |
150 | bad = __get_user(val, &((u32 *)addr)[i]); | |
151 | ||
152 | if (!bad) | |
d191fe09 RK |
153 | p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ", |
154 | width, val); | |
1da177e4 | 155 | else { |
d191fe09 | 156 | p += sprintf(p, "bad PC value"); |
1da177e4 LT |
157 | break; |
158 | } | |
159 | } | |
e40c2ec6 | 160 | printk("%sCode: %s\n", lvl, str); |
1da177e4 LT |
161 | |
162 | set_fs(fs); | |
163 | } | |
164 | ||
bff595c1 CM |
165 | #ifdef CONFIG_ARM_UNWIND |
166 | static inline void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) | |
167 | { | |
168 | unwind_backtrace(regs, tsk); | |
169 | } | |
170 | #else | |
1da177e4 LT |
171 | static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) |
172 | { | |
67a94c23 | 173 | unsigned int fp, mode; |
1da177e4 LT |
174 | int ok = 1; |
175 | ||
176 | printk("Backtrace: "); | |
67a94c23 CM |
177 | |
178 | if (!tsk) | |
179 | tsk = current; | |
180 | ||
181 | if (regs) { | |
182 | fp = regs->ARM_fp; | |
183 | mode = processor_mode(regs); | |
184 | } else if (tsk != current) { | |
185 | fp = thread_saved_fp(tsk); | |
186 | mode = 0x10; | |
187 | } else { | |
188 | asm("mov %0, fp" : "=r" (fp) : : "cc"); | |
189 | mode = 0x10; | |
190 | } | |
191 | ||
1da177e4 LT |
192 | if (!fp) { |
193 | printk("no frame pointer"); | |
194 | ok = 0; | |
195 | } else if (verify_stack(fp)) { | |
196 | printk("invalid frame pointer 0x%08x", fp); | |
197 | ok = 0; | |
55205823 | 198 | } else if (fp < (unsigned long)end_of_stack(tsk)) |
1da177e4 LT |
199 | printk("frame pointer underflow"); |
200 | printk("\n"); | |
201 | ||
202 | if (ok) | |
67a94c23 | 203 | c_backtrace(fp, mode); |
1da177e4 | 204 | } |
bff595c1 | 205 | #endif |
1da177e4 LT |
206 | |
207 | void dump_stack(void) | |
208 | { | |
67a94c23 | 209 | dump_backtrace(NULL, NULL); |
1da177e4 LT |
210 | } |
211 | ||
212 | EXPORT_SYMBOL(dump_stack); | |
213 | ||
214 | void show_stack(struct task_struct *tsk, unsigned long *sp) | |
215 | { | |
67a94c23 | 216 | dump_backtrace(NULL, tsk); |
1da177e4 LT |
217 | barrier(); |
218 | } | |
219 | ||
d9202429 RK |
220 | #ifdef CONFIG_PREEMPT |
221 | #define S_PREEMPT " PREEMPT" | |
222 | #else | |
223 | #define S_PREEMPT "" | |
224 | #endif | |
225 | #ifdef CONFIG_SMP | |
226 | #define S_SMP " SMP" | |
227 | #else | |
228 | #define S_SMP "" | |
229 | #endif | |
8211ca65 RK |
230 | #ifdef CONFIG_THUMB2_KERNEL |
231 | #define S_ISA " THUMB2" | |
232 | #else | |
233 | #define S_ISA " ARM" | |
234 | #endif | |
d9202429 | 235 | |
a9221de6 | 236 | static int __die(const char *str, int err, struct thread_info *thread, struct pt_regs *regs) |
1da177e4 | 237 | { |
d362979a | 238 | struct task_struct *tsk = thread->task; |
1da177e4 | 239 | static int die_counter; |
a9221de6 | 240 | int ret; |
1da177e4 | 241 | |
8211ca65 RK |
242 | printk(KERN_EMERG "Internal error: %s: %x [#%d]" S_PREEMPT S_SMP |
243 | S_ISA "\n", str, err, ++die_counter); | |
a9221de6 RK |
244 | |
245 | /* trap and error numbers are mostly meaningless on ARM */ | |
246 | ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, SIGSEGV); | |
247 | if (ret == NOTIFY_STOP) | |
248 | return ret; | |
249 | ||
1da177e4 | 250 | print_modules(); |
652a12ef | 251 | __show_regs(regs); |
e40c2ec6 RK |
252 | printk(KERN_EMERG "Process %.*s (pid: %d, stack limit = 0x%p)\n", |
253 | TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1); | |
1da177e4 LT |
254 | |
255 | if (!user_mode(regs) || in_interrupt()) { | |
e40c2ec6 | 256 | dump_mem(KERN_EMERG, "Stack: ", regs->ARM_sp, |
32d39a93 | 257 | THREAD_SIZE + (unsigned long)task_stack_page(tsk)); |
1da177e4 | 258 | dump_backtrace(regs, tsk); |
e40c2ec6 | 259 | dump_instr(KERN_EMERG, regs); |
1da177e4 | 260 | } |
a9221de6 RK |
261 | |
262 | return ret; | |
d362979a | 263 | } |
1da177e4 | 264 | |
bd31b859 | 265 | static DEFINE_RAW_SPINLOCK(die_lock); |
d362979a RK |
266 | |
267 | /* | |
268 | * This function is protected against re-entrancy. | |
269 | */ | |
a9221de6 | 270 | void die(const char *str, struct pt_regs *regs, int err) |
d362979a RK |
271 | { |
272 | struct thread_info *thread = current_thread_info(); | |
a9221de6 | 273 | int ret; |
bdf800c4 | 274 | enum bug_trap_type bug_type = BUG_TRAP_TYPE_NONE; |
d362979a | 275 | |
d9202429 RK |
276 | oops_enter(); |
277 | ||
bd31b859 | 278 | raw_spin_lock_irq(&die_lock); |
03a6e5bd | 279 | console_verbose(); |
d362979a | 280 | bust_spinlocks(1); |
87e040b6 | 281 | if (!user_mode(regs)) |
bdf800c4 SB |
282 | bug_type = report_bug(regs->ARM_pc, regs); |
283 | if (bug_type != BUG_TRAP_TYPE_NONE) | |
284 | str = "Oops - BUG"; | |
a9221de6 RK |
285 | ret = __die(str, err, thread, regs); |
286 | ||
287 | if (regs && kexec_should_crash(thread->task)) | |
288 | crash_kexec(regs); | |
289 | ||
1da177e4 | 290 | bust_spinlocks(0); |
bcdcd8e7 | 291 | add_taint(TAINT_DIE); |
bd31b859 | 292 | raw_spin_unlock_irq(&die_lock); |
03a6e5bd | 293 | oops_exit(); |
31867499 | 294 | |
d9202429 RK |
295 | if (in_interrupt()) |
296 | panic("Fatal exception in interrupt"); | |
cea6a4ba | 297 | if (panic_on_oops) |
012c437d | 298 | panic("Fatal exception"); |
a9221de6 RK |
299 | if (ret != NOTIFY_STOP) |
300 | do_exit(SIGSEGV); | |
1da177e4 LT |
301 | } |
302 | ||
1eeb66a1 CH |
303 | void arm_notify_die(const char *str, struct pt_regs *regs, |
304 | struct siginfo *info, unsigned long err, unsigned long trap) | |
1da177e4 LT |
305 | { |
306 | if (user_mode(regs)) { | |
307 | current->thread.error_code = err; | |
308 | current->thread.trap_no = trap; | |
309 | ||
310 | force_sig_info(info->si_signo, info, current); | |
311 | } else { | |
312 | die(str, regs, err); | |
313 | } | |
314 | } | |
315 | ||
87e040b6 SG |
316 | #ifdef CONFIG_GENERIC_BUG |
317 | ||
318 | int is_valid_bugaddr(unsigned long pc) | |
319 | { | |
320 | #ifdef CONFIG_THUMB2_KERNEL | |
321 | unsigned short bkpt; | |
322 | #else | |
323 | unsigned long bkpt; | |
324 | #endif | |
325 | ||
326 | if (probe_kernel_address((unsigned *)pc, bkpt)) | |
327 | return 0; | |
328 | ||
329 | return bkpt == BUG_INSTR_VALUE; | |
330 | } | |
331 | ||
332 | #endif | |
333 | ||
1da177e4 | 334 | static LIST_HEAD(undef_hook); |
bd31b859 | 335 | static DEFINE_RAW_SPINLOCK(undef_lock); |
1da177e4 LT |
336 | |
337 | void register_undef_hook(struct undef_hook *hook) | |
338 | { | |
109d89ca RK |
339 | unsigned long flags; |
340 | ||
bd31b859 | 341 | raw_spin_lock_irqsave(&undef_lock, flags); |
1da177e4 | 342 | list_add(&hook->node, &undef_hook); |
bd31b859 | 343 | raw_spin_unlock_irqrestore(&undef_lock, flags); |
1da177e4 LT |
344 | } |
345 | ||
346 | void unregister_undef_hook(struct undef_hook *hook) | |
347 | { | |
109d89ca RK |
348 | unsigned long flags; |
349 | ||
bd31b859 | 350 | raw_spin_lock_irqsave(&undef_lock, flags); |
1da177e4 | 351 | list_del(&hook->node); |
bd31b859 | 352 | raw_spin_unlock_irqrestore(&undef_lock, flags); |
1da177e4 LT |
353 | } |
354 | ||
b03a5b75 RK |
355 | static int call_undef_hook(struct pt_regs *regs, unsigned int instr) |
356 | { | |
357 | struct undef_hook *hook; | |
358 | unsigned long flags; | |
359 | int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL; | |
360 | ||
bd31b859 | 361 | raw_spin_lock_irqsave(&undef_lock, flags); |
b03a5b75 RK |
362 | list_for_each_entry(hook, &undef_hook, node) |
363 | if ((instr & hook->instr_mask) == hook->instr_val && | |
364 | (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val) | |
365 | fn = hook->fn; | |
bd31b859 | 366 | raw_spin_unlock_irqrestore(&undef_lock, flags); |
b03a5b75 RK |
367 | |
368 | return fn ? fn(regs, instr) : 1; | |
369 | } | |
370 | ||
7ab3f8d5 | 371 | asmlinkage void __exception do_undefinstr(struct pt_regs *regs) |
1da177e4 LT |
372 | { |
373 | unsigned int correction = thumb_mode(regs) ? 2 : 4; | |
374 | unsigned int instr; | |
1da177e4 LT |
375 | siginfo_t info; |
376 | void __user *pc; | |
377 | ||
378 | /* | |
379 | * According to the ARM ARM, PC is 2 or 4 bytes ahead, | |
380 | * depending whether we're in Thumb mode or not. | |
381 | * Correct this offset. | |
382 | */ | |
383 | regs->ARM_pc -= correction; | |
384 | ||
385 | pc = (void __user *)instruction_pointer(regs); | |
dfc544c7 DW |
386 | |
387 | if (processor_mode(regs) == SVC_MODE) { | |
592201a9 JM |
388 | #ifdef CONFIG_THUMB2_KERNEL |
389 | if (thumb_mode(regs)) { | |
390 | instr = ((u16 *)pc)[0]; | |
391 | if (is_wide_instruction(instr)) { | |
392 | instr <<= 16; | |
393 | instr |= ((u16 *)pc)[1]; | |
394 | } | |
395 | } else | |
396 | #endif | |
397 | instr = *(u32 *) pc; | |
dfc544c7 | 398 | } else if (thumb_mode(regs)) { |
1da177e4 | 399 | get_user(instr, (u16 __user *)pc); |
592201a9 JM |
400 | if (is_wide_instruction(instr)) { |
401 | unsigned int instr2; | |
402 | get_user(instr2, (u16 __user *)pc+1); | |
403 | instr <<= 16; | |
404 | instr |= instr2; | |
405 | } | |
1da177e4 LT |
406 | } else { |
407 | get_user(instr, (u32 __user *)pc); | |
408 | } | |
409 | ||
b03a5b75 RK |
410 | if (call_undef_hook(regs, instr) == 0) |
411 | return; | |
1da177e4 LT |
412 | |
413 | #ifdef CONFIG_DEBUG_USER | |
414 | if (user_debug & UDBG_UNDEFINED) { | |
415 | printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n", | |
19c5870c | 416 | current->comm, task_pid_nr(current), pc); |
e40c2ec6 | 417 | dump_instr(KERN_INFO, regs); |
1da177e4 LT |
418 | } |
419 | #endif | |
420 | ||
421 | info.si_signo = SIGILL; | |
422 | info.si_errno = 0; | |
423 | info.si_code = ILL_ILLOPC; | |
424 | info.si_addr = pc; | |
425 | ||
1eeb66a1 | 426 | arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6); |
1da177e4 LT |
427 | } |
428 | ||
429 | asmlinkage void do_unexp_fiq (struct pt_regs *regs) | |
430 | { | |
1da177e4 LT |
431 | printk("Hmm. Unexpected FIQ received, but trying to continue\n"); |
432 | printk("You may have a hardware problem...\n"); | |
1da177e4 LT |
433 | } |
434 | ||
435 | /* | |
436 | * bad_mode handles the impossible case in the vectors. If you see one of | |
437 | * these, then it's extremely serious, and could mean you have buggy hardware. | |
438 | * It never returns, and never tries to sync. We hope that we can at least | |
439 | * dump out some state information... | |
440 | */ | |
ae0a846e | 441 | asmlinkage void bad_mode(struct pt_regs *regs, int reason) |
1da177e4 LT |
442 | { |
443 | console_verbose(); | |
444 | ||
ae0a846e | 445 | printk(KERN_CRIT "Bad mode in %s handler detected\n", handler[reason]); |
1da177e4 LT |
446 | |
447 | die("Oops - bad mode", regs, 0); | |
448 | local_irq_disable(); | |
449 | panic("bad mode"); | |
450 | } | |
451 | ||
452 | static int bad_syscall(int n, struct pt_regs *regs) | |
453 | { | |
454 | struct thread_info *thread = current_thread_info(); | |
455 | siginfo_t info; | |
456 | ||
88b9ef45 | 457 | if ((current->personality & PER_MASK) != PER_LINUX && |
a999cb04 | 458 | thread->exec_domain->handler) { |
1da177e4 LT |
459 | thread->exec_domain->handler(n, regs); |
460 | return regs->ARM_r0; | |
461 | } | |
462 | ||
463 | #ifdef CONFIG_DEBUG_USER | |
464 | if (user_debug & UDBG_SYSCALL) { | |
465 | printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n", | |
19c5870c | 466 | task_pid_nr(current), current->comm, n); |
e40c2ec6 | 467 | dump_instr(KERN_ERR, regs); |
1da177e4 LT |
468 | } |
469 | #endif | |
470 | ||
471 | info.si_signo = SIGILL; | |
472 | info.si_errno = 0; | |
473 | info.si_code = ILL_ILLTRP; | |
474 | info.si_addr = (void __user *)instruction_pointer(regs) - | |
475 | (thumb_mode(regs) ? 2 : 4); | |
476 | ||
1eeb66a1 | 477 | arm_notify_die("Oops - bad syscall", regs, &info, n, 0); |
1da177e4 LT |
478 | |
479 | return regs->ARM_r0; | |
480 | } | |
481 | ||
c5102f59 | 482 | static inline int |
1da177e4 LT |
483 | do_cache_op(unsigned long start, unsigned long end, int flags) |
484 | { | |
aa45ee8f | 485 | struct mm_struct *mm = current->active_mm; |
1da177e4 LT |
486 | struct vm_area_struct *vma; |
487 | ||
488 | if (end < start || flags) | |
c5102f59 | 489 | return -EINVAL; |
1da177e4 | 490 | |
aa45ee8f RK |
491 | down_read(&mm->mmap_sem); |
492 | vma = find_vma(mm, start); | |
1da177e4 LT |
493 | if (vma && vma->vm_start < end) { |
494 | if (start < vma->vm_start) | |
495 | start = vma->vm_start; | |
496 | if (end > vma->vm_end) | |
497 | end = vma->vm_end; | |
498 | ||
435a7ef5 | 499 | up_read(&mm->mmap_sem); |
c5102f59 | 500 | return flush_cache_user_range(start, end); |
1da177e4 | 501 | } |
aa45ee8f | 502 | up_read(&mm->mmap_sem); |
c5102f59 | 503 | return -EINVAL; |
1da177e4 LT |
504 | } |
505 | ||
506 | /* | |
507 | * Handle all unrecognised system calls. | |
508 | * 0x9f0000 - 0x9fffff are some more esoteric system calls | |
509 | */ | |
510 | #define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE) | |
511 | asmlinkage int arm_syscall(int no, struct pt_regs *regs) | |
512 | { | |
513 | struct thread_info *thread = current_thread_info(); | |
514 | siginfo_t info; | |
515 | ||
3f2829a3 | 516 | if ((no >> 16) != (__ARM_NR_BASE>> 16)) |
1da177e4 LT |
517 | return bad_syscall(no, regs); |
518 | ||
519 | switch (no & 0xffff) { | |
520 | case 0: /* branch through 0 */ | |
521 | info.si_signo = SIGSEGV; | |
522 | info.si_errno = 0; | |
523 | info.si_code = SEGV_MAPERR; | |
524 | info.si_addr = NULL; | |
525 | ||
1eeb66a1 | 526 | arm_notify_die("branch through zero", regs, &info, 0, 0); |
1da177e4 LT |
527 | return 0; |
528 | ||
529 | case NR(breakpoint): /* SWI BREAK_POINT */ | |
530 | regs->ARM_pc -= thumb_mode(regs) ? 2 : 4; | |
531 | ptrace_break(current, regs); | |
532 | return regs->ARM_r0; | |
533 | ||
534 | /* | |
535 | * Flush a region from virtual address 'r0' to virtual address 'r1' | |
536 | * _exclusive_. There is no alignment requirement on either address; | |
537 | * user space does not need to know the hardware cache layout. | |
538 | * | |
539 | * r2 contains flags. It should ALWAYS be passed as ZERO until it | |
540 | * is defined to be something else. For now we ignore it, but may | |
541 | * the fires of hell burn in your belly if you break this rule. ;) | |
542 | * | |
543 | * (at a later date, we may want to allow this call to not flush | |
544 | * various aspects of the cache. Passing '0' will guarantee that | |
545 | * everything necessary gets flushed to maintain consistency in | |
546 | * the specified region). | |
547 | */ | |
548 | case NR(cacheflush): | |
c5102f59 | 549 | return do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2); |
1da177e4 LT |
550 | |
551 | case NR(usr26): | |
552 | if (!(elf_hwcap & HWCAP_26BIT)) | |
553 | break; | |
554 | regs->ARM_cpsr &= ~MODE32_BIT; | |
555 | return regs->ARM_r0; | |
556 | ||
557 | case NR(usr32): | |
558 | if (!(elf_hwcap & HWCAP_26BIT)) | |
559 | break; | |
560 | regs->ARM_cpsr |= MODE32_BIT; | |
561 | return regs->ARM_r0; | |
562 | ||
563 | case NR(set_tls): | |
564 | thread->tp_value = regs->ARM_r0; | |
f159f4ed TL |
565 | if (tls_emu) |
566 | return 0; | |
567 | if (has_tls_reg) { | |
568 | asm ("mcr p15, 0, %0, c13, c0, 3" | |
569 | : : "r" (regs->ARM_r0)); | |
570 | } else { | |
571 | /* | |
572 | * User space must never try to access this directly. | |
573 | * Expect your app to break eventually if you do so. | |
574 | * The user helper at 0xffff0fe0 must be used instead. | |
575 | * (see entry-armv.S for details) | |
576 | */ | |
577 | *((unsigned int *)0xffff0ff0) = regs->ARM_r0; | |
578 | } | |
1da177e4 LT |
579 | return 0; |
580 | ||
dcef1f63 NP |
581 | #ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG |
582 | /* | |
583 | * Atomically store r1 in *r2 if *r2 is equal to r0 for user space. | |
584 | * Return zero in r0 if *MEM was changed or non-zero if no exchange | |
585 | * happened. Also set the user C flag accordingly. | |
586 | * If access permissions have to be fixed up then non-zero is | |
587 | * returned and the operation has to be re-attempted. | |
588 | * | |
589 | * *NOTE*: This is a ghost syscall private to the kernel. Only the | |
590 | * __kuser_cmpxchg code in entry-armv.S should be aware of its | |
591 | * existence. Don't ever use this from user code. | |
592 | */ | |
cc20d429 | 593 | case NR(cmpxchg): |
b49c0f24 | 594 | for (;;) { |
dcef1f63 NP |
595 | extern void do_DataAbort(unsigned long addr, unsigned int fsr, |
596 | struct pt_regs *regs); | |
597 | unsigned long val; | |
598 | unsigned long addr = regs->ARM_r2; | |
599 | struct mm_struct *mm = current->mm; | |
600 | pgd_t *pgd; pmd_t *pmd; pte_t *pte; | |
69b04754 | 601 | spinlock_t *ptl; |
dcef1f63 NP |
602 | |
603 | regs->ARM_cpsr &= ~PSR_C_BIT; | |
69b04754 | 604 | down_read(&mm->mmap_sem); |
dcef1f63 NP |
605 | pgd = pgd_offset(mm, addr); |
606 | if (!pgd_present(*pgd)) | |
607 | goto bad_access; | |
608 | pmd = pmd_offset(pgd, addr); | |
609 | if (!pmd_present(*pmd)) | |
610 | goto bad_access; | |
69b04754 | 611 | pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
373ce302 | 612 | if (!pte_present(*pte) || !pte_write(*pte) || !pte_dirty(*pte)) { |
69b04754 | 613 | pte_unmap_unlock(pte, ptl); |
dcef1f63 | 614 | goto bad_access; |
69b04754 | 615 | } |
dcef1f63 NP |
616 | val = *(unsigned long *)addr; |
617 | val -= regs->ARM_r0; | |
618 | if (val == 0) { | |
619 | *(unsigned long *)addr = regs->ARM_r1; | |
620 | regs->ARM_cpsr |= PSR_C_BIT; | |
621 | } | |
69b04754 HD |
622 | pte_unmap_unlock(pte, ptl); |
623 | up_read(&mm->mmap_sem); | |
dcef1f63 NP |
624 | return val; |
625 | ||
626 | bad_access: | |
69b04754 | 627 | up_read(&mm->mmap_sem); |
74f88494 | 628 | /* simulate a write access fault */ |
dcef1f63 | 629 | do_DataAbort(addr, 15 + (1 << 11), regs); |
dcef1f63 NP |
630 | } |
631 | #endif | |
632 | ||
1da177e4 LT |
633 | default: |
634 | /* Calls 9f00xx..9f07ff are defined to return -ENOSYS | |
635 | if not implemented, rather than raising SIGILL. This | |
636 | way the calling program can gracefully determine whether | |
637 | a feature is supported. */ | |
bfd2e29f | 638 | if ((no & 0xffff) <= 0x7ff) |
1da177e4 LT |
639 | return -ENOSYS; |
640 | break; | |
641 | } | |
642 | #ifdef CONFIG_DEBUG_USER | |
643 | /* | |
644 | * experience shows that these seem to indicate that | |
645 | * something catastrophic has happened | |
646 | */ | |
647 | if (user_debug & UDBG_SYSCALL) { | |
648 | printk("[%d] %s: arm syscall %d\n", | |
19c5870c | 649 | task_pid_nr(current), current->comm, no); |
e40c2ec6 | 650 | dump_instr("", regs); |
1da177e4 | 651 | if (user_mode(regs)) { |
652a12ef | 652 | __show_regs(regs); |
1da177e4 LT |
653 | c_backtrace(regs->ARM_fp, processor_mode(regs)); |
654 | } | |
655 | } | |
656 | #endif | |
657 | info.si_signo = SIGILL; | |
658 | info.si_errno = 0; | |
659 | info.si_code = ILL_ILLTRP; | |
660 | info.si_addr = (void __user *)instruction_pointer(regs) - | |
661 | (thumb_mode(regs) ? 2 : 4); | |
662 | ||
1eeb66a1 | 663 | arm_notify_die("Oops - bad syscall(2)", regs, &info, no, 0); |
1da177e4 LT |
664 | return 0; |
665 | } | |
666 | ||
4b0e07a5 | 667 | #ifdef CONFIG_TLS_REG_EMUL |
2d2669b6 NP |
668 | |
669 | /* | |
670 | * We might be running on an ARMv6+ processor which should have the TLS | |
4b0e07a5 NP |
671 | * register but for some reason we can't use it, or maybe an SMP system |
672 | * using a pre-ARMv6 processor (there are apparently a few prototypes like | |
673 | * that in existence) and therefore access to that register must be | |
674 | * emulated. | |
2d2669b6 NP |
675 | */ |
676 | ||
677 | static int get_tp_trap(struct pt_regs *regs, unsigned int instr) | |
678 | { | |
679 | int reg = (instr >> 12) & 15; | |
680 | if (reg == 15) | |
681 | return 1; | |
682 | regs->uregs[reg] = current_thread_info()->tp_value; | |
683 | regs->ARM_pc += 4; | |
684 | return 0; | |
685 | } | |
686 | ||
687 | static struct undef_hook arm_mrc_hook = { | |
688 | .instr_mask = 0x0fff0fff, | |
689 | .instr_val = 0x0e1d0f70, | |
690 | .cpsr_mask = PSR_T_BIT, | |
691 | .cpsr_val = 0, | |
692 | .fn = get_tp_trap, | |
693 | }; | |
694 | ||
695 | static int __init arm_mrc_hook_init(void) | |
696 | { | |
697 | register_undef_hook(&arm_mrc_hook); | |
698 | return 0; | |
699 | } | |
700 | ||
701 | late_initcall(arm_mrc_hook_init); | |
702 | ||
703 | #endif | |
704 | ||
1da177e4 LT |
705 | void __bad_xchg(volatile void *ptr, int size) |
706 | { | |
707 | printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n", | |
708 | __builtin_return_address(0), ptr, size); | |
709 | BUG(); | |
710 | } | |
711 | EXPORT_SYMBOL(__bad_xchg); | |
712 | ||
713 | /* | |
714 | * A data abort trap was taken, but we did not handle the instruction. | |
715 | * Try to abort the user program, or panic if it was the kernel. | |
716 | */ | |
717 | asmlinkage void | |
718 | baddataabort(int code, unsigned long instr, struct pt_regs *regs) | |
719 | { | |
720 | unsigned long addr = instruction_pointer(regs); | |
721 | siginfo_t info; | |
722 | ||
723 | #ifdef CONFIG_DEBUG_USER | |
724 | if (user_debug & UDBG_BADABORT) { | |
725 | printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n", | |
19c5870c | 726 | task_pid_nr(current), current->comm, code, instr); |
e40c2ec6 | 727 | dump_instr(KERN_ERR, regs); |
1da177e4 LT |
728 | show_pte(current->mm, addr); |
729 | } | |
730 | #endif | |
731 | ||
732 | info.si_signo = SIGILL; | |
733 | info.si_errno = 0; | |
734 | info.si_code = ILL_ILLOPC; | |
735 | info.si_addr = (void __user *)addr; | |
736 | ||
1eeb66a1 | 737 | arm_notify_die("unknown data abort code", regs, &info, instr, 0); |
1da177e4 LT |
738 | } |
739 | ||
1da177e4 LT |
740 | void __readwrite_bug(const char *fn) |
741 | { | |
742 | printk("%s called, but not implemented\n", fn); | |
743 | BUG(); | |
744 | } | |
745 | EXPORT_SYMBOL(__readwrite_bug); | |
746 | ||
69529c0e | 747 | void __pte_error(const char *file, int line, pte_t pte) |
1da177e4 | 748 | { |
29a38193 | 749 | printk("%s:%d: bad pte %08llx.\n", file, line, (long long)pte_val(pte)); |
1da177e4 LT |
750 | } |
751 | ||
69529c0e | 752 | void __pmd_error(const char *file, int line, pmd_t pmd) |
1da177e4 | 753 | { |
29a38193 | 754 | printk("%s:%d: bad pmd %08llx.\n", file, line, (long long)pmd_val(pmd)); |
1da177e4 LT |
755 | } |
756 | ||
69529c0e | 757 | void __pgd_error(const char *file, int line, pgd_t pgd) |
1da177e4 | 758 | { |
29a38193 | 759 | printk("%s:%d: bad pgd %08llx.\n", file, line, (long long)pgd_val(pgd)); |
1da177e4 LT |
760 | } |
761 | ||
762 | asmlinkage void __div0(void) | |
763 | { | |
764 | printk("Division by zero in kernel.\n"); | |
765 | dump_stack(); | |
766 | } | |
767 | EXPORT_SYMBOL(__div0); | |
768 | ||
769 | void abort(void) | |
770 | { | |
771 | BUG(); | |
772 | ||
773 | /* if that doesn't kill us, halt */ | |
774 | panic("Oops failed to kill thread"); | |
775 | } | |
776 | EXPORT_SYMBOL(abort); | |
777 | ||
778 | void __init trap_init(void) | |
5cbad0eb JW |
779 | { |
780 | return; | |
781 | } | |
782 | ||
f159f4ed TL |
783 | static void __init kuser_get_tls_init(unsigned long vectors) |
784 | { | |
785 | /* | |
786 | * vectors + 0xfe0 = __kuser_get_tls | |
787 | * vectors + 0xfe8 = hardware TLS instruction at 0xffff0fe8 | |
788 | */ | |
789 | if (tls_emu || has_tls_reg) | |
790 | memcpy((void *)vectors + 0xfe0, (void *)vectors + 0xfe8, 4); | |
791 | } | |
792 | ||
94e5a85b | 793 | void __init early_trap_init(void *vectors_base) |
1da177e4 | 794 | { |
94e5a85b | 795 | unsigned long vectors = (unsigned long)vectors_base; |
7933523d RK |
796 | extern char __stubs_start[], __stubs_end[]; |
797 | extern char __vectors_start[], __vectors_end[]; | |
2d2669b6 NP |
798 | extern char __kuser_helper_start[], __kuser_helper_end[]; |
799 | int kuser_sz = __kuser_helper_end - __kuser_helper_start; | |
1da177e4 | 800 | |
94e5a85b RK |
801 | vectors_page = vectors_base; |
802 | ||
7933523d | 803 | /* |
2d2669b6 NP |
804 | * Copy the vectors, stubs and kuser helpers (in entry-armv.S) |
805 | * into the vector page, mapped at 0xffff0000, and ensure these | |
806 | * are visible to the instruction stream. | |
7933523d | 807 | */ |
c760fc19 HC |
808 | memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start); |
809 | memcpy((void *)vectors + 0x200, __stubs_start, __stubs_end - __stubs_start); | |
810 | memcpy((void *)vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz); | |
e00d349e | 811 | |
f159f4ed TL |
812 | /* |
813 | * Do processor specific fixups for the kuser helpers | |
814 | */ | |
815 | kuser_get_tls_init(vectors); | |
816 | ||
e00d349e RK |
817 | /* |
818 | * Copy signal return handlers into the vector page, and | |
819 | * set sigreturn to be a pointer to these. | |
820 | */ | |
247055aa CM |
821 | memcpy((void *)(vectors + KERN_SIGRETURN_CODE - CONFIG_VECTORS_BASE), |
822 | sigreturn_codes, sizeof(sigreturn_codes)); | |
3b0c0622 WD |
823 | memcpy((void *)(vectors + KERN_RESTART_CODE - CONFIG_VECTORS_BASE), |
824 | syscall_restart_code, sizeof(syscall_restart_code)); | |
e00d349e | 825 | |
c760fc19 | 826 | flush_icache_range(vectors, vectors + PAGE_SIZE); |
1da177e4 LT |
827 | modify_domain(DOMAIN_USER, DOMAIN_CLIENT); |
828 | } |