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 | |
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 | ||
a9011580 | 142 | for (i = -4; i < 1 + !!thumb; i++) { |
1da177e4 LT |
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 | 204 | |
1da177e4 LT |
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 | |
8211ca65 RK |
221 | #ifdef CONFIG_THUMB2_KERNEL |
222 | #define S_ISA " THUMB2" | |
223 | #else | |
224 | #define S_ISA " ARM" | |
225 | #endif | |
d9202429 | 226 | |
02df19b4 | 227 | static int __die(const char *str, int err, struct pt_regs *regs) |
1da177e4 | 228 | { |
02df19b4 | 229 | struct task_struct *tsk = current; |
1da177e4 | 230 | static int die_counter; |
a9221de6 | 231 | int ret; |
1da177e4 | 232 | |
8211ca65 RK |
233 | printk(KERN_EMERG "Internal error: %s: %x [#%d]" S_PREEMPT S_SMP |
234 | S_ISA "\n", str, err, ++die_counter); | |
a9221de6 RK |
235 | |
236 | /* trap and error numbers are mostly meaningless on ARM */ | |
237 | ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, SIGSEGV); | |
238 | if (ret == NOTIFY_STOP) | |
02df19b4 | 239 | return 1; |
a9221de6 | 240 | |
1da177e4 | 241 | print_modules(); |
652a12ef | 242 | __show_regs(regs); |
e40c2ec6 | 243 | printk(KERN_EMERG "Process %.*s (pid: %d, stack limit = 0x%p)\n", |
02df19b4 | 244 | TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), end_of_stack(tsk)); |
1da177e4 LT |
245 | |
246 | if (!user_mode(regs) || in_interrupt()) { | |
e40c2ec6 | 247 | dump_mem(KERN_EMERG, "Stack: ", regs->ARM_sp, |
32d39a93 | 248 | THREAD_SIZE + (unsigned long)task_stack_page(tsk)); |
1da177e4 | 249 | dump_backtrace(regs, tsk); |
e40c2ec6 | 250 | dump_instr(KERN_EMERG, regs); |
1da177e4 | 251 | } |
a9221de6 | 252 | |
02df19b4 | 253 | return 0; |
d362979a | 254 | } |
1da177e4 | 255 | |
02df19b4 RV |
256 | static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED; |
257 | static int die_owner = -1; | |
258 | static unsigned int die_nest_count; | |
d362979a | 259 | |
02df19b4 | 260 | static unsigned long oops_begin(void) |
d362979a | 261 | { |
02df19b4 RV |
262 | int cpu; |
263 | unsigned long flags; | |
d362979a | 264 | |
d9202429 RK |
265 | oops_enter(); |
266 | ||
02df19b4 RV |
267 | /* racy, but better than risking deadlock. */ |
268 | raw_local_irq_save(flags); | |
269 | cpu = smp_processor_id(); | |
270 | if (!arch_spin_trylock(&die_lock)) { | |
271 | if (cpu == die_owner) | |
272 | /* nested oops. should stop eventually */; | |
273 | else | |
274 | arch_spin_lock(&die_lock); | |
275 | } | |
276 | die_nest_count++; | |
277 | die_owner = cpu; | |
03a6e5bd | 278 | console_verbose(); |
d362979a | 279 | bust_spinlocks(1); |
02df19b4 RV |
280 | return flags; |
281 | } | |
a9221de6 | 282 | |
02df19b4 RV |
283 | static void oops_end(unsigned long flags, struct pt_regs *regs, int signr) |
284 | { | |
285 | if (regs && kexec_should_crash(current)) | |
a9221de6 RK |
286 | crash_kexec(regs); |
287 | ||
1da177e4 | 288 | bust_spinlocks(0); |
02df19b4 | 289 | die_owner = -1; |
373d4d09 | 290 | add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); |
02df19b4 RV |
291 | die_nest_count--; |
292 | if (!die_nest_count) | |
293 | /* Nest count reaches zero, release the lock. */ | |
294 | arch_spin_unlock(&die_lock); | |
295 | raw_local_irq_restore(flags); | |
03a6e5bd | 296 | oops_exit(); |
31867499 | 297 | |
d9202429 RK |
298 | if (in_interrupt()) |
299 | panic("Fatal exception in interrupt"); | |
cea6a4ba | 300 | if (panic_on_oops) |
012c437d | 301 | panic("Fatal exception"); |
02df19b4 RV |
302 | if (signr) |
303 | do_exit(signr); | |
304 | } | |
305 | ||
306 | /* | |
307 | * This function is protected against re-entrancy. | |
308 | */ | |
309 | void die(const char *str, struct pt_regs *regs, int err) | |
310 | { | |
311 | enum bug_trap_type bug_type = BUG_TRAP_TYPE_NONE; | |
312 | unsigned long flags = oops_begin(); | |
313 | int sig = SIGSEGV; | |
314 | ||
315 | if (!user_mode(regs)) | |
316 | bug_type = report_bug(regs->ARM_pc, regs); | |
317 | if (bug_type != BUG_TRAP_TYPE_NONE) | |
318 | str = "Oops - BUG"; | |
319 | ||
320 | if (__die(str, err, regs)) | |
321 | sig = 0; | |
322 | ||
323 | oops_end(flags, regs, sig); | |
1da177e4 LT |
324 | } |
325 | ||
1eeb66a1 CH |
326 | void arm_notify_die(const char *str, struct pt_regs *regs, |
327 | struct siginfo *info, unsigned long err, unsigned long trap) | |
1da177e4 LT |
328 | { |
329 | if (user_mode(regs)) { | |
330 | current->thread.error_code = err; | |
331 | current->thread.trap_no = trap; | |
332 | ||
333 | force_sig_info(info->si_signo, info, current); | |
334 | } else { | |
335 | die(str, regs, err); | |
336 | } | |
337 | } | |
338 | ||
87e040b6 SG |
339 | #ifdef CONFIG_GENERIC_BUG |
340 | ||
341 | int is_valid_bugaddr(unsigned long pc) | |
342 | { | |
343 | #ifdef CONFIG_THUMB2_KERNEL | |
344 | unsigned short bkpt; | |
345 | #else | |
346 | unsigned long bkpt; | |
347 | #endif | |
348 | ||
349 | if (probe_kernel_address((unsigned *)pc, bkpt)) | |
350 | return 0; | |
351 | ||
352 | return bkpt == BUG_INSTR_VALUE; | |
353 | } | |
354 | ||
355 | #endif | |
356 | ||
1da177e4 | 357 | static LIST_HEAD(undef_hook); |
bd31b859 | 358 | static DEFINE_RAW_SPINLOCK(undef_lock); |
1da177e4 LT |
359 | |
360 | void register_undef_hook(struct undef_hook *hook) | |
361 | { | |
109d89ca RK |
362 | unsigned long flags; |
363 | ||
bd31b859 | 364 | raw_spin_lock_irqsave(&undef_lock, flags); |
1da177e4 | 365 | list_add(&hook->node, &undef_hook); |
bd31b859 | 366 | raw_spin_unlock_irqrestore(&undef_lock, flags); |
1da177e4 LT |
367 | } |
368 | ||
369 | void unregister_undef_hook(struct undef_hook *hook) | |
370 | { | |
109d89ca RK |
371 | unsigned long flags; |
372 | ||
bd31b859 | 373 | raw_spin_lock_irqsave(&undef_lock, flags); |
1da177e4 | 374 | list_del(&hook->node); |
bd31b859 | 375 | raw_spin_unlock_irqrestore(&undef_lock, flags); |
1da177e4 LT |
376 | } |
377 | ||
b03a5b75 RK |
378 | static int call_undef_hook(struct pt_regs *regs, unsigned int instr) |
379 | { | |
380 | struct undef_hook *hook; | |
381 | unsigned long flags; | |
382 | int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL; | |
383 | ||
bd31b859 | 384 | raw_spin_lock_irqsave(&undef_lock, flags); |
b03a5b75 RK |
385 | list_for_each_entry(hook, &undef_hook, node) |
386 | if ((instr & hook->instr_mask) == hook->instr_val && | |
387 | (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val) | |
388 | fn = hook->fn; | |
bd31b859 | 389 | raw_spin_unlock_irqrestore(&undef_lock, flags); |
b03a5b75 RK |
390 | |
391 | return fn ? fn(regs, instr) : 1; | |
392 | } | |
393 | ||
7ab3f8d5 | 394 | asmlinkage void __exception do_undefinstr(struct pt_regs *regs) |
1da177e4 | 395 | { |
1da177e4 | 396 | unsigned int instr; |
1da177e4 LT |
397 | siginfo_t info; |
398 | void __user *pc; | |
399 | ||
1da177e4 | 400 | pc = (void __user *)instruction_pointer(regs); |
dfc544c7 DW |
401 | |
402 | if (processor_mode(regs) == SVC_MODE) { | |
592201a9 JM |
403 | #ifdef CONFIG_THUMB2_KERNEL |
404 | if (thumb_mode(regs)) { | |
405 | instr = ((u16 *)pc)[0]; | |
406 | if (is_wide_instruction(instr)) { | |
407 | instr <<= 16; | |
408 | instr |= ((u16 *)pc)[1]; | |
409 | } | |
410 | } else | |
411 | #endif | |
412 | instr = *(u32 *) pc; | |
dfc544c7 | 413 | } else if (thumb_mode(regs)) { |
2b2040af WD |
414 | if (get_user(instr, (u16 __user *)pc)) |
415 | goto die_sig; | |
592201a9 JM |
416 | if (is_wide_instruction(instr)) { |
417 | unsigned int instr2; | |
2b2040af WD |
418 | if (get_user(instr2, (u16 __user *)pc+1)) |
419 | goto die_sig; | |
592201a9 JM |
420 | instr <<= 16; |
421 | instr |= instr2; | |
422 | } | |
2b2040af WD |
423 | } else if (get_user(instr, (u32 __user *)pc)) { |
424 | goto die_sig; | |
1da177e4 LT |
425 | } |
426 | ||
b03a5b75 RK |
427 | if (call_undef_hook(regs, instr) == 0) |
428 | return; | |
1da177e4 | 429 | |
2b2040af | 430 | die_sig: |
1da177e4 LT |
431 | #ifdef CONFIG_DEBUG_USER |
432 | if (user_debug & UDBG_UNDEFINED) { | |
433 | printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n", | |
19c5870c | 434 | current->comm, task_pid_nr(current), pc); |
e40c2ec6 | 435 | dump_instr(KERN_INFO, regs); |
1da177e4 LT |
436 | } |
437 | #endif | |
438 | ||
439 | info.si_signo = SIGILL; | |
440 | info.si_errno = 0; | |
441 | info.si_code = ILL_ILLOPC; | |
442 | info.si_addr = pc; | |
443 | ||
1eeb66a1 | 444 | arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6); |
1da177e4 LT |
445 | } |
446 | ||
447 | asmlinkage void do_unexp_fiq (struct pt_regs *regs) | |
448 | { | |
1da177e4 LT |
449 | printk("Hmm. Unexpected FIQ received, but trying to continue\n"); |
450 | printk("You may have a hardware problem...\n"); | |
1da177e4 LT |
451 | } |
452 | ||
453 | /* | |
454 | * bad_mode handles the impossible case in the vectors. If you see one of | |
455 | * these, then it's extremely serious, and could mean you have buggy hardware. | |
456 | * It never returns, and never tries to sync. We hope that we can at least | |
457 | * dump out some state information... | |
458 | */ | |
ae0a846e | 459 | asmlinkage void bad_mode(struct pt_regs *regs, int reason) |
1da177e4 LT |
460 | { |
461 | console_verbose(); | |
462 | ||
ae0a846e | 463 | printk(KERN_CRIT "Bad mode in %s handler detected\n", handler[reason]); |
1da177e4 LT |
464 | |
465 | die("Oops - bad mode", regs, 0); | |
466 | local_irq_disable(); | |
467 | panic("bad mode"); | |
468 | } | |
469 | ||
470 | static int bad_syscall(int n, struct pt_regs *regs) | |
471 | { | |
472 | struct thread_info *thread = current_thread_info(); | |
473 | siginfo_t info; | |
474 | ||
88b9ef45 | 475 | if ((current->personality & PER_MASK) != PER_LINUX && |
a999cb04 | 476 | thread->exec_domain->handler) { |
1da177e4 LT |
477 | thread->exec_domain->handler(n, regs); |
478 | return regs->ARM_r0; | |
479 | } | |
480 | ||
481 | #ifdef CONFIG_DEBUG_USER | |
482 | if (user_debug & UDBG_SYSCALL) { | |
483 | printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n", | |
19c5870c | 484 | task_pid_nr(current), current->comm, n); |
e40c2ec6 | 485 | dump_instr(KERN_ERR, regs); |
1da177e4 LT |
486 | } |
487 | #endif | |
488 | ||
489 | info.si_signo = SIGILL; | |
490 | info.si_errno = 0; | |
491 | info.si_code = ILL_ILLTRP; | |
492 | info.si_addr = (void __user *)instruction_pointer(regs) - | |
493 | (thumb_mode(regs) ? 2 : 4); | |
494 | ||
1eeb66a1 | 495 | arm_notify_die("Oops - bad syscall", regs, &info, n, 0); |
1da177e4 LT |
496 | |
497 | return regs->ARM_r0; | |
498 | } | |
499 | ||
c5102f59 | 500 | static inline int |
1da177e4 LT |
501 | do_cache_op(unsigned long start, unsigned long end, int flags) |
502 | { | |
aa45ee8f | 503 | struct mm_struct *mm = current->active_mm; |
1da177e4 LT |
504 | struct vm_area_struct *vma; |
505 | ||
506 | if (end < start || flags) | |
c5102f59 | 507 | return -EINVAL; |
1da177e4 | 508 | |
aa45ee8f RK |
509 | down_read(&mm->mmap_sem); |
510 | vma = find_vma(mm, start); | |
1da177e4 LT |
511 | if (vma && vma->vm_start < end) { |
512 | if (start < vma->vm_start) | |
513 | start = vma->vm_start; | |
514 | if (end > vma->vm_end) | |
515 | end = vma->vm_end; | |
516 | ||
435a7ef5 | 517 | up_read(&mm->mmap_sem); |
c5102f59 | 518 | return flush_cache_user_range(start, end); |
1da177e4 | 519 | } |
aa45ee8f | 520 | up_read(&mm->mmap_sem); |
c5102f59 | 521 | return -EINVAL; |
1da177e4 LT |
522 | } |
523 | ||
524 | /* | |
525 | * Handle all unrecognised system calls. | |
526 | * 0x9f0000 - 0x9fffff are some more esoteric system calls | |
527 | */ | |
528 | #define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE) | |
529 | asmlinkage int arm_syscall(int no, struct pt_regs *regs) | |
530 | { | |
531 | struct thread_info *thread = current_thread_info(); | |
532 | siginfo_t info; | |
533 | ||
3f2829a3 | 534 | if ((no >> 16) != (__ARM_NR_BASE>> 16)) |
1da177e4 LT |
535 | return bad_syscall(no, regs); |
536 | ||
537 | switch (no & 0xffff) { | |
538 | case 0: /* branch through 0 */ | |
539 | info.si_signo = SIGSEGV; | |
540 | info.si_errno = 0; | |
541 | info.si_code = SEGV_MAPERR; | |
542 | info.si_addr = NULL; | |
543 | ||
1eeb66a1 | 544 | arm_notify_die("branch through zero", regs, &info, 0, 0); |
1da177e4 LT |
545 | return 0; |
546 | ||
547 | case NR(breakpoint): /* SWI BREAK_POINT */ | |
548 | regs->ARM_pc -= thumb_mode(regs) ? 2 : 4; | |
549 | ptrace_break(current, regs); | |
550 | return regs->ARM_r0; | |
551 | ||
552 | /* | |
553 | * Flush a region from virtual address 'r0' to virtual address 'r1' | |
554 | * _exclusive_. There is no alignment requirement on either address; | |
555 | * user space does not need to know the hardware cache layout. | |
556 | * | |
557 | * r2 contains flags. It should ALWAYS be passed as ZERO until it | |
558 | * is defined to be something else. For now we ignore it, but may | |
559 | * the fires of hell burn in your belly if you break this rule. ;) | |
560 | * | |
561 | * (at a later date, we may want to allow this call to not flush | |
562 | * various aspects of the cache. Passing '0' will guarantee that | |
563 | * everything necessary gets flushed to maintain consistency in | |
564 | * the specified region). | |
565 | */ | |
566 | case NR(cacheflush): | |
c5102f59 | 567 | return do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2); |
1da177e4 LT |
568 | |
569 | case NR(usr26): | |
570 | if (!(elf_hwcap & HWCAP_26BIT)) | |
571 | break; | |
572 | regs->ARM_cpsr &= ~MODE32_BIT; | |
573 | return regs->ARM_r0; | |
574 | ||
575 | case NR(usr32): | |
576 | if (!(elf_hwcap & HWCAP_26BIT)) | |
577 | break; | |
578 | regs->ARM_cpsr |= MODE32_BIT; | |
579 | return regs->ARM_r0; | |
580 | ||
581 | case NR(set_tls): | |
a4780ade | 582 | thread->tp_value[0] = regs->ARM_r0; |
f159f4ed TL |
583 | if (tls_emu) |
584 | return 0; | |
585 | if (has_tls_reg) { | |
586 | asm ("mcr p15, 0, %0, c13, c0, 3" | |
587 | : : "r" (regs->ARM_r0)); | |
588 | } else { | |
589 | /* | |
590 | * User space must never try to access this directly. | |
591 | * Expect your app to break eventually if you do so. | |
592 | * The user helper at 0xffff0fe0 must be used instead. | |
593 | * (see entry-armv.S for details) | |
594 | */ | |
595 | *((unsigned int *)0xffff0ff0) = regs->ARM_r0; | |
596 | } | |
1da177e4 LT |
597 | return 0; |
598 | ||
dcef1f63 NP |
599 | #ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG |
600 | /* | |
601 | * Atomically store r1 in *r2 if *r2 is equal to r0 for user space. | |
602 | * Return zero in r0 if *MEM was changed or non-zero if no exchange | |
603 | * happened. Also set the user C flag accordingly. | |
604 | * If access permissions have to be fixed up then non-zero is | |
605 | * returned and the operation has to be re-attempted. | |
606 | * | |
607 | * *NOTE*: This is a ghost syscall private to the kernel. Only the | |
608 | * __kuser_cmpxchg code in entry-armv.S should be aware of its | |
609 | * existence. Don't ever use this from user code. | |
610 | */ | |
cc20d429 | 611 | case NR(cmpxchg): |
b49c0f24 | 612 | for (;;) { |
dcef1f63 NP |
613 | extern void do_DataAbort(unsigned long addr, unsigned int fsr, |
614 | struct pt_regs *regs); | |
615 | unsigned long val; | |
616 | unsigned long addr = regs->ARM_r2; | |
617 | struct mm_struct *mm = current->mm; | |
618 | pgd_t *pgd; pmd_t *pmd; pte_t *pte; | |
69b04754 | 619 | spinlock_t *ptl; |
dcef1f63 NP |
620 | |
621 | regs->ARM_cpsr &= ~PSR_C_BIT; | |
69b04754 | 622 | down_read(&mm->mmap_sem); |
dcef1f63 NP |
623 | pgd = pgd_offset(mm, addr); |
624 | if (!pgd_present(*pgd)) | |
625 | goto bad_access; | |
626 | pmd = pmd_offset(pgd, addr); | |
627 | if (!pmd_present(*pmd)) | |
628 | goto bad_access; | |
69b04754 | 629 | pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
373ce302 | 630 | if (!pte_present(*pte) || !pte_write(*pte) || !pte_dirty(*pte)) { |
69b04754 | 631 | pte_unmap_unlock(pte, ptl); |
dcef1f63 | 632 | goto bad_access; |
69b04754 | 633 | } |
dcef1f63 NP |
634 | val = *(unsigned long *)addr; |
635 | val -= regs->ARM_r0; | |
636 | if (val == 0) { | |
637 | *(unsigned long *)addr = regs->ARM_r1; | |
638 | regs->ARM_cpsr |= PSR_C_BIT; | |
639 | } | |
69b04754 HD |
640 | pte_unmap_unlock(pte, ptl); |
641 | up_read(&mm->mmap_sem); | |
dcef1f63 NP |
642 | return val; |
643 | ||
644 | bad_access: | |
69b04754 | 645 | up_read(&mm->mmap_sem); |
74f88494 | 646 | /* simulate a write access fault */ |
dcef1f63 | 647 | do_DataAbort(addr, 15 + (1 << 11), regs); |
dcef1f63 NP |
648 | } |
649 | #endif | |
650 | ||
1da177e4 LT |
651 | default: |
652 | /* Calls 9f00xx..9f07ff are defined to return -ENOSYS | |
653 | if not implemented, rather than raising SIGILL. This | |
654 | way the calling program can gracefully determine whether | |
655 | a feature is supported. */ | |
bfd2e29f | 656 | if ((no & 0xffff) <= 0x7ff) |
1da177e4 LT |
657 | return -ENOSYS; |
658 | break; | |
659 | } | |
660 | #ifdef CONFIG_DEBUG_USER | |
661 | /* | |
662 | * experience shows that these seem to indicate that | |
663 | * something catastrophic has happened | |
664 | */ | |
665 | if (user_debug & UDBG_SYSCALL) { | |
666 | printk("[%d] %s: arm syscall %d\n", | |
19c5870c | 667 | task_pid_nr(current), current->comm, no); |
e40c2ec6 | 668 | dump_instr("", regs); |
1da177e4 | 669 | if (user_mode(regs)) { |
652a12ef | 670 | __show_regs(regs); |
1da177e4 LT |
671 | c_backtrace(regs->ARM_fp, processor_mode(regs)); |
672 | } | |
673 | } | |
674 | #endif | |
675 | info.si_signo = SIGILL; | |
676 | info.si_errno = 0; | |
677 | info.si_code = ILL_ILLTRP; | |
678 | info.si_addr = (void __user *)instruction_pointer(regs) - | |
679 | (thumb_mode(regs) ? 2 : 4); | |
680 | ||
1eeb66a1 | 681 | arm_notify_die("Oops - bad syscall(2)", regs, &info, no, 0); |
1da177e4 LT |
682 | return 0; |
683 | } | |
684 | ||
4b0e07a5 | 685 | #ifdef CONFIG_TLS_REG_EMUL |
2d2669b6 NP |
686 | |
687 | /* | |
688 | * We might be running on an ARMv6+ processor which should have the TLS | |
4b0e07a5 NP |
689 | * register but for some reason we can't use it, or maybe an SMP system |
690 | * using a pre-ARMv6 processor (there are apparently a few prototypes like | |
691 | * that in existence) and therefore access to that register must be | |
692 | * emulated. | |
2d2669b6 NP |
693 | */ |
694 | ||
695 | static int get_tp_trap(struct pt_regs *regs, unsigned int instr) | |
696 | { | |
697 | int reg = (instr >> 12) & 15; | |
698 | if (reg == 15) | |
699 | return 1; | |
a4780ade | 700 | regs->uregs[reg] = current_thread_info()->tp_value[0]; |
2d2669b6 NP |
701 | regs->ARM_pc += 4; |
702 | return 0; | |
703 | } | |
704 | ||
705 | static struct undef_hook arm_mrc_hook = { | |
706 | .instr_mask = 0x0fff0fff, | |
707 | .instr_val = 0x0e1d0f70, | |
708 | .cpsr_mask = PSR_T_BIT, | |
709 | .cpsr_val = 0, | |
710 | .fn = get_tp_trap, | |
711 | }; | |
712 | ||
713 | static int __init arm_mrc_hook_init(void) | |
714 | { | |
715 | register_undef_hook(&arm_mrc_hook); | |
716 | return 0; | |
717 | } | |
718 | ||
719 | late_initcall(arm_mrc_hook_init); | |
720 | ||
721 | #endif | |
722 | ||
1da177e4 LT |
723 | void __bad_xchg(volatile void *ptr, int size) |
724 | { | |
725 | printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n", | |
726 | __builtin_return_address(0), ptr, size); | |
727 | BUG(); | |
728 | } | |
729 | EXPORT_SYMBOL(__bad_xchg); | |
730 | ||
731 | /* | |
732 | * A data abort trap was taken, but we did not handle the instruction. | |
733 | * Try to abort the user program, or panic if it was the kernel. | |
734 | */ | |
735 | asmlinkage void | |
736 | baddataabort(int code, unsigned long instr, struct pt_regs *regs) | |
737 | { | |
738 | unsigned long addr = instruction_pointer(regs); | |
739 | siginfo_t info; | |
740 | ||
741 | #ifdef CONFIG_DEBUG_USER | |
742 | if (user_debug & UDBG_BADABORT) { | |
743 | printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n", | |
19c5870c | 744 | task_pid_nr(current), current->comm, code, instr); |
e40c2ec6 | 745 | dump_instr(KERN_ERR, regs); |
1da177e4 LT |
746 | show_pte(current->mm, addr); |
747 | } | |
748 | #endif | |
749 | ||
750 | info.si_signo = SIGILL; | |
751 | info.si_errno = 0; | |
752 | info.si_code = ILL_ILLOPC; | |
753 | info.si_addr = (void __user *)addr; | |
754 | ||
1eeb66a1 | 755 | arm_notify_die("unknown data abort code", regs, &info, instr, 0); |
1da177e4 LT |
756 | } |
757 | ||
1da177e4 LT |
758 | void __readwrite_bug(const char *fn) |
759 | { | |
760 | printk("%s called, but not implemented\n", fn); | |
761 | BUG(); | |
762 | } | |
763 | EXPORT_SYMBOL(__readwrite_bug); | |
764 | ||
69529c0e | 765 | void __pte_error(const char *file, int line, pte_t pte) |
1da177e4 | 766 | { |
29a38193 | 767 | printk("%s:%d: bad pte %08llx.\n", file, line, (long long)pte_val(pte)); |
1da177e4 LT |
768 | } |
769 | ||
69529c0e | 770 | void __pmd_error(const char *file, int line, pmd_t pmd) |
1da177e4 | 771 | { |
29a38193 | 772 | printk("%s:%d: bad pmd %08llx.\n", file, line, (long long)pmd_val(pmd)); |
1da177e4 LT |
773 | } |
774 | ||
69529c0e | 775 | void __pgd_error(const char *file, int line, pgd_t pgd) |
1da177e4 | 776 | { |
29a38193 | 777 | printk("%s:%d: bad pgd %08llx.\n", file, line, (long long)pgd_val(pgd)); |
1da177e4 LT |
778 | } |
779 | ||
780 | asmlinkage void __div0(void) | |
781 | { | |
782 | printk("Division by zero in kernel.\n"); | |
783 | dump_stack(); | |
784 | } | |
785 | EXPORT_SYMBOL(__div0); | |
786 | ||
787 | void abort(void) | |
788 | { | |
789 | BUG(); | |
790 | ||
791 | /* if that doesn't kill us, halt */ | |
792 | panic("Oops failed to kill thread"); | |
793 | } | |
794 | EXPORT_SYMBOL(abort); | |
795 | ||
796 | void __init trap_init(void) | |
5cbad0eb JW |
797 | { |
798 | return; | |
799 | } | |
800 | ||
f6f91b0d RK |
801 | #ifdef CONFIG_KUSER_HELPERS |
802 | static void __init kuser_init(void *vectors) | |
f159f4ed | 803 | { |
f6f91b0d RK |
804 | extern char __kuser_helper_start[], __kuser_helper_end[]; |
805 | int kuser_sz = __kuser_helper_end - __kuser_helper_start; | |
806 | ||
807 | memcpy(vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz); | |
808 | ||
f159f4ed TL |
809 | /* |
810 | * vectors + 0xfe0 = __kuser_get_tls | |
811 | * vectors + 0xfe8 = hardware TLS instruction at 0xffff0fe8 | |
812 | */ | |
813 | if (tls_emu || has_tls_reg) | |
f6f91b0d RK |
814 | memcpy(vectors + 0xfe0, vectors + 0xfe8, 4); |
815 | } | |
816 | #else | |
817 | static void __init kuser_init(void *vectors) | |
818 | { | |
f159f4ed | 819 | } |
f6f91b0d | 820 | #endif |
f159f4ed | 821 | |
94e5a85b | 822 | void __init early_trap_init(void *vectors_base) |
1da177e4 | 823 | { |
55bdd694 | 824 | #ifndef CONFIG_CPU_V7M |
94e5a85b | 825 | unsigned long vectors = (unsigned long)vectors_base; |
7933523d RK |
826 | extern char __stubs_start[], __stubs_end[]; |
827 | extern char __vectors_start[], __vectors_end[]; | |
f928d4f2 | 828 | unsigned i; |
1da177e4 | 829 | |
94e5a85b RK |
830 | vectors_page = vectors_base; |
831 | ||
f928d4f2 RK |
832 | /* |
833 | * Poison the vectors page with an undefined instruction. This | |
834 | * instruction is chosen to be undefined for both ARM and Thumb | |
835 | * ISAs. The Thumb version is an undefined instruction with a | |
836 | * branch back to the undefined instruction. | |
837 | */ | |
838 | for (i = 0; i < PAGE_SIZE / sizeof(u32); i++) | |
839 | ((u32 *)vectors_base)[i] = 0xe7fddef1; | |
840 | ||
7933523d | 841 | /* |
2d2669b6 NP |
842 | * Copy the vectors, stubs and kuser helpers (in entry-armv.S) |
843 | * into the vector page, mapped at 0xffff0000, and ensure these | |
844 | * are visible to the instruction stream. | |
7933523d | 845 | */ |
c760fc19 | 846 | memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start); |
19accfd3 | 847 | memcpy((void *)vectors + 0x1000, __stubs_start, __stubs_end - __stubs_start); |
e00d349e | 848 | |
f6f91b0d | 849 | kuser_init(vectors_base); |
f159f4ed | 850 | |
19accfd3 | 851 | flush_icache_range(vectors, vectors + PAGE_SIZE * 2); |
1da177e4 | 852 | modify_domain(DOMAIN_USER, DOMAIN_CLIENT); |
55bdd694 CM |
853 | #else /* ifndef CONFIG_CPU_V7M */ |
854 | /* | |
855 | * on V7-M there is no need to copy the vector table to a dedicated | |
856 | * memory area. The address is configurable and so a table in the kernel | |
857 | * image can be used. | |
858 | */ | |
859 | #endif | |
1da177e4 | 860 | } |