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> |
a79a0cb1 | 37 | #include <asm/opcodes.h> |
1da177e4 | 38 | |
1da177e4 LT |
39 | static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" }; |
40 | ||
247055aa CM |
41 | void *vectors_page; |
42 | ||
1da177e4 LT |
43 | #ifdef CONFIG_DEBUG_USER |
44 | unsigned int user_debug; | |
45 | ||
46 | static int __init user_debug_setup(char *str) | |
47 | { | |
48 | get_option(&str, &user_debug); | |
49 | return 1; | |
50 | } | |
51 | __setup("user_debug=", user_debug_setup); | |
52 | #endif | |
53 | ||
e40c2ec6 | 54 | static void dump_mem(const char *, const char *, unsigned long, unsigned long); |
7ab3f8d5 | 55 | |
7ab3f8d5 | 56 | void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame) |
1da177e4 LT |
57 | { |
58 | #ifdef CONFIG_KALLSYMS | |
69448c2a | 59 | printk("[<%08lx>] (%pS) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from); |
1da177e4 LT |
60 | #else |
61 | printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from); | |
62 | #endif | |
7ab3f8d5 RK |
63 | |
64 | if (in_exception_text(where)) | |
e40c2ec6 | 65 | dump_mem("", "Exception stack", frame + 4, frame + 4 + sizeof(struct pt_regs)); |
1da177e4 LT |
66 | } |
67 | ||
bff595c1 | 68 | #ifndef CONFIG_ARM_UNWIND |
1da177e4 LT |
69 | /* |
70 | * Stack pointers should always be within the kernels view of | |
71 | * physical memory. If it is not there, then we can't dump | |
72 | * out any information relating to the stack. | |
73 | */ | |
74 | static int verify_stack(unsigned long sp) | |
75 | { | |
09d9bae0 RK |
76 | if (sp < PAGE_OFFSET || |
77 | (sp > (unsigned long)high_memory && high_memory != NULL)) | |
1da177e4 LT |
78 | return -EFAULT; |
79 | ||
80 | return 0; | |
81 | } | |
bff595c1 | 82 | #endif |
1da177e4 LT |
83 | |
84 | /* | |
85 | * Dump out the contents of some memory nicely... | |
86 | */ | |
e40c2ec6 RK |
87 | static void dump_mem(const char *lvl, const char *str, unsigned long bottom, |
88 | unsigned long top) | |
1da177e4 | 89 | { |
d191fe09 | 90 | unsigned long first; |
1da177e4 LT |
91 | mm_segment_t fs; |
92 | int i; | |
93 | ||
94 | /* | |
95 | * We need to switch to kernel mode so that we can use __get_user | |
96 | * to safely read from kernel space. Note that we now dump the | |
97 | * code first, just in case the backtrace kills us. | |
98 | */ | |
99 | fs = get_fs(); | |
100 | set_fs(KERNEL_DS); | |
101 | ||
e40c2ec6 | 102 | printk("%s%s(0x%08lx to 0x%08lx)\n", lvl, str, bottom, top); |
1da177e4 | 103 | |
d191fe09 RK |
104 | for (first = bottom & ~31; first < top; first += 32) { |
105 | unsigned long p; | |
106 | char str[sizeof(" 12345678") * 8 + 1]; | |
1da177e4 | 107 | |
d191fe09 RK |
108 | memset(str, ' ', sizeof(str)); |
109 | str[sizeof(str) - 1] = '\0'; | |
1da177e4 | 110 | |
d191fe09 RK |
111 | for (p = first, i = 0; i < 8 && p < top; i++, p += 4) { |
112 | if (p >= bottom && p < top) { | |
113 | unsigned long val; | |
114 | if (__get_user(val, (unsigned long *)p) == 0) | |
115 | sprintf(str + i * 9, " %08lx", val); | |
116 | else | |
117 | sprintf(str + i * 9, " ????????"); | |
1da177e4 LT |
118 | } |
119 | } | |
e40c2ec6 | 120 | printk("%s%04lx:%s\n", lvl, first & 0xffff, str); |
1da177e4 LT |
121 | } |
122 | ||
123 | set_fs(fs); | |
124 | } | |
125 | ||
e40c2ec6 | 126 | static void dump_instr(const char *lvl, struct pt_regs *regs) |
1da177e4 LT |
127 | { |
128 | unsigned long addr = instruction_pointer(regs); | |
129 | const int thumb = thumb_mode(regs); | |
130 | const int width = thumb ? 4 : 8; | |
131 | mm_segment_t fs; | |
d191fe09 | 132 | char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str; |
1da177e4 LT |
133 | int i; |
134 | ||
135 | /* | |
136 | * We need to switch to kernel mode so that we can use __get_user | |
137 | * to safely read from kernel space. Note that we now dump the | |
138 | * code first, just in case the backtrace kills us. | |
139 | */ | |
140 | fs = get_fs(); | |
141 | set_fs(KERNEL_DS); | |
142 | ||
a9011580 | 143 | for (i = -4; i < 1 + !!thumb; i++) { |
1da177e4 LT |
144 | unsigned int val, bad; |
145 | ||
146 | if (thumb) | |
147 | bad = __get_user(val, &((u16 *)addr)[i]); | |
148 | else | |
149 | bad = __get_user(val, &((u32 *)addr)[i]); | |
150 | ||
151 | if (!bad) | |
d191fe09 RK |
152 | p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ", |
153 | width, val); | |
1da177e4 | 154 | else { |
d191fe09 | 155 | p += sprintf(p, "bad PC value"); |
1da177e4 LT |
156 | break; |
157 | } | |
158 | } | |
e40c2ec6 | 159 | printk("%sCode: %s\n", lvl, str); |
1da177e4 LT |
160 | |
161 | set_fs(fs); | |
162 | } | |
163 | ||
bff595c1 CM |
164 | #ifdef CONFIG_ARM_UNWIND |
165 | static inline void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) | |
166 | { | |
167 | unwind_backtrace(regs, tsk); | |
168 | } | |
169 | #else | |
1da177e4 LT |
170 | static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) |
171 | { | |
67a94c23 | 172 | unsigned int fp, mode; |
1da177e4 LT |
173 | int ok = 1; |
174 | ||
175 | printk("Backtrace: "); | |
67a94c23 CM |
176 | |
177 | if (!tsk) | |
178 | tsk = current; | |
179 | ||
180 | if (regs) { | |
181 | fp = regs->ARM_fp; | |
182 | mode = processor_mode(regs); | |
183 | } else if (tsk != current) { | |
184 | fp = thread_saved_fp(tsk); | |
185 | mode = 0x10; | |
186 | } else { | |
187 | asm("mov %0, fp" : "=r" (fp) : : "cc"); | |
188 | mode = 0x10; | |
189 | } | |
190 | ||
1da177e4 LT |
191 | if (!fp) { |
192 | printk("no frame pointer"); | |
193 | ok = 0; | |
194 | } else if (verify_stack(fp)) { | |
195 | printk("invalid frame pointer 0x%08x", fp); | |
196 | ok = 0; | |
55205823 | 197 | } else if (fp < (unsigned long)end_of_stack(tsk)) |
1da177e4 LT |
198 | printk("frame pointer underflow"); |
199 | printk("\n"); | |
200 | ||
201 | if (ok) | |
67a94c23 | 202 | c_backtrace(fp, mode); |
1da177e4 | 203 | } |
bff595c1 | 204 | #endif |
1da177e4 | 205 | |
1da177e4 LT |
206 | void show_stack(struct task_struct *tsk, unsigned long *sp) |
207 | { | |
67a94c23 | 208 | dump_backtrace(NULL, tsk); |
1da177e4 LT |
209 | barrier(); |
210 | } | |
211 | ||
d9202429 RK |
212 | #ifdef CONFIG_PREEMPT |
213 | #define S_PREEMPT " PREEMPT" | |
214 | #else | |
215 | #define S_PREEMPT "" | |
216 | #endif | |
217 | #ifdef CONFIG_SMP | |
218 | #define S_SMP " SMP" | |
219 | #else | |
220 | #define S_SMP "" | |
221 | #endif | |
8211ca65 RK |
222 | #ifdef CONFIG_THUMB2_KERNEL |
223 | #define S_ISA " THUMB2" | |
224 | #else | |
225 | #define S_ISA " ARM" | |
226 | #endif | |
d9202429 | 227 | |
02df19b4 | 228 | static int __die(const char *str, int err, struct pt_regs *regs) |
1da177e4 | 229 | { |
02df19b4 | 230 | struct task_struct *tsk = current; |
1da177e4 | 231 | static int die_counter; |
a9221de6 | 232 | int ret; |
1da177e4 | 233 | |
8211ca65 RK |
234 | printk(KERN_EMERG "Internal error: %s: %x [#%d]" S_PREEMPT S_SMP |
235 | S_ISA "\n", str, err, ++die_counter); | |
a9221de6 RK |
236 | |
237 | /* trap and error numbers are mostly meaningless on ARM */ | |
238 | ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, SIGSEGV); | |
239 | if (ret == NOTIFY_STOP) | |
02df19b4 | 240 | return 1; |
a9221de6 | 241 | |
1da177e4 | 242 | print_modules(); |
652a12ef | 243 | __show_regs(regs); |
e40c2ec6 | 244 | printk(KERN_EMERG "Process %.*s (pid: %d, stack limit = 0x%p)\n", |
02df19b4 | 245 | TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), end_of_stack(tsk)); |
1da177e4 LT |
246 | |
247 | if (!user_mode(regs) || in_interrupt()) { | |
e40c2ec6 | 248 | dump_mem(KERN_EMERG, "Stack: ", regs->ARM_sp, |
32d39a93 | 249 | THREAD_SIZE + (unsigned long)task_stack_page(tsk)); |
1da177e4 | 250 | dump_backtrace(regs, tsk); |
e40c2ec6 | 251 | dump_instr(KERN_EMERG, regs); |
1da177e4 | 252 | } |
a9221de6 | 253 | |
02df19b4 | 254 | return 0; |
d362979a | 255 | } |
1da177e4 | 256 | |
02df19b4 RV |
257 | static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED; |
258 | static int die_owner = -1; | |
259 | static unsigned int die_nest_count; | |
d362979a | 260 | |
02df19b4 | 261 | static unsigned long oops_begin(void) |
d362979a | 262 | { |
02df19b4 RV |
263 | int cpu; |
264 | unsigned long flags; | |
d362979a | 265 | |
d9202429 RK |
266 | oops_enter(); |
267 | ||
02df19b4 RV |
268 | /* racy, but better than risking deadlock. */ |
269 | raw_local_irq_save(flags); | |
270 | cpu = smp_processor_id(); | |
271 | if (!arch_spin_trylock(&die_lock)) { | |
272 | if (cpu == die_owner) | |
273 | /* nested oops. should stop eventually */; | |
274 | else | |
275 | arch_spin_lock(&die_lock); | |
276 | } | |
277 | die_nest_count++; | |
278 | die_owner = cpu; | |
03a6e5bd | 279 | console_verbose(); |
d362979a | 280 | bust_spinlocks(1); |
02df19b4 RV |
281 | return flags; |
282 | } | |
a9221de6 | 283 | |
02df19b4 RV |
284 | static void oops_end(unsigned long flags, struct pt_regs *regs, int signr) |
285 | { | |
286 | if (regs && kexec_should_crash(current)) | |
a9221de6 RK |
287 | crash_kexec(regs); |
288 | ||
1da177e4 | 289 | bust_spinlocks(0); |
02df19b4 | 290 | die_owner = -1; |
373d4d09 | 291 | add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); |
02df19b4 RV |
292 | die_nest_count--; |
293 | if (!die_nest_count) | |
294 | /* Nest count reaches zero, release the lock. */ | |
295 | arch_spin_unlock(&die_lock); | |
296 | raw_local_irq_restore(flags); | |
03a6e5bd | 297 | oops_exit(); |
31867499 | 298 | |
d9202429 RK |
299 | if (in_interrupt()) |
300 | panic("Fatal exception in interrupt"); | |
cea6a4ba | 301 | if (panic_on_oops) |
012c437d | 302 | panic("Fatal exception"); |
02df19b4 RV |
303 | if (signr) |
304 | do_exit(signr); | |
305 | } | |
306 | ||
307 | /* | |
308 | * This function is protected against re-entrancy. | |
309 | */ | |
310 | void die(const char *str, struct pt_regs *regs, int err) | |
311 | { | |
312 | enum bug_trap_type bug_type = BUG_TRAP_TYPE_NONE; | |
313 | unsigned long flags = oops_begin(); | |
314 | int sig = SIGSEGV; | |
315 | ||
316 | if (!user_mode(regs)) | |
317 | bug_type = report_bug(regs->ARM_pc, regs); | |
318 | if (bug_type != BUG_TRAP_TYPE_NONE) | |
319 | str = "Oops - BUG"; | |
320 | ||
321 | if (__die(str, err, regs)) | |
322 | sig = 0; | |
323 | ||
324 | oops_end(flags, regs, sig); | |
1da177e4 LT |
325 | } |
326 | ||
1eeb66a1 CH |
327 | void arm_notify_die(const char *str, struct pt_regs *regs, |
328 | struct siginfo *info, unsigned long err, unsigned long trap) | |
1da177e4 LT |
329 | { |
330 | if (user_mode(regs)) { | |
331 | current->thread.error_code = err; | |
332 | current->thread.trap_no = trap; | |
333 | ||
334 | force_sig_info(info->si_signo, info, current); | |
335 | } else { | |
336 | die(str, regs, err); | |
337 | } | |
338 | } | |
339 | ||
87e040b6 SG |
340 | #ifdef CONFIG_GENERIC_BUG |
341 | ||
342 | int is_valid_bugaddr(unsigned long pc) | |
343 | { | |
344 | #ifdef CONFIG_THUMB2_KERNEL | |
63328070 BD |
345 | u16 bkpt; |
346 | u16 insn = __opcode_to_mem_thumb16(BUG_INSTR_VALUE); | |
87e040b6 | 347 | #else |
63328070 BD |
348 | u32 bkpt; |
349 | u32 insn = __opcode_to_mem_arm(BUG_INSTR_VALUE); | |
87e040b6 SG |
350 | #endif |
351 | ||
352 | if (probe_kernel_address((unsigned *)pc, bkpt)) | |
353 | return 0; | |
354 | ||
63328070 | 355 | return bkpt == insn; |
87e040b6 SG |
356 | } |
357 | ||
358 | #endif | |
359 | ||
1da177e4 | 360 | static LIST_HEAD(undef_hook); |
bd31b859 | 361 | static DEFINE_RAW_SPINLOCK(undef_lock); |
1da177e4 LT |
362 | |
363 | void register_undef_hook(struct undef_hook *hook) | |
364 | { | |
109d89ca RK |
365 | unsigned long flags; |
366 | ||
bd31b859 | 367 | raw_spin_lock_irqsave(&undef_lock, flags); |
1da177e4 | 368 | list_add(&hook->node, &undef_hook); |
bd31b859 | 369 | raw_spin_unlock_irqrestore(&undef_lock, flags); |
1da177e4 LT |
370 | } |
371 | ||
372 | void unregister_undef_hook(struct undef_hook *hook) | |
373 | { | |
109d89ca RK |
374 | unsigned long flags; |
375 | ||
bd31b859 | 376 | raw_spin_lock_irqsave(&undef_lock, flags); |
1da177e4 | 377 | list_del(&hook->node); |
bd31b859 | 378 | raw_spin_unlock_irqrestore(&undef_lock, flags); |
1da177e4 LT |
379 | } |
380 | ||
b03a5b75 RK |
381 | static int call_undef_hook(struct pt_regs *regs, unsigned int instr) |
382 | { | |
383 | struct undef_hook *hook; | |
384 | unsigned long flags; | |
385 | int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL; | |
386 | ||
bd31b859 | 387 | raw_spin_lock_irqsave(&undef_lock, flags); |
b03a5b75 RK |
388 | list_for_each_entry(hook, &undef_hook, node) |
389 | if ((instr & hook->instr_mask) == hook->instr_val && | |
390 | (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val) | |
391 | fn = hook->fn; | |
bd31b859 | 392 | raw_spin_unlock_irqrestore(&undef_lock, flags); |
b03a5b75 RK |
393 | |
394 | return fn ? fn(regs, instr) : 1; | |
395 | } | |
396 | ||
7ab3f8d5 | 397 | asmlinkage void __exception do_undefinstr(struct pt_regs *regs) |
1da177e4 | 398 | { |
1da177e4 | 399 | unsigned int instr; |
1da177e4 LT |
400 | siginfo_t info; |
401 | void __user *pc; | |
402 | ||
1da177e4 | 403 | pc = (void __user *)instruction_pointer(regs); |
dfc544c7 DW |
404 | |
405 | if (processor_mode(regs) == SVC_MODE) { | |
592201a9 JM |
406 | #ifdef CONFIG_THUMB2_KERNEL |
407 | if (thumb_mode(regs)) { | |
a79a0cb1 | 408 | instr = __mem_to_opcode_thumb16(((u16 *)pc)[0]); |
592201a9 | 409 | if (is_wide_instruction(instr)) { |
a79a0cb1 BD |
410 | u16 inst2; |
411 | inst2 = __mem_to_opcode_thumb16(((u16 *)pc)[1]); | |
412 | instr = __opcode_thumb32_compose(instr, inst2); | |
592201a9 JM |
413 | } |
414 | } else | |
415 | #endif | |
a79a0cb1 | 416 | instr = __mem_to_opcode_arm(*(u32 *) pc); |
dfc544c7 | 417 | } else if (thumb_mode(regs)) { |
2b2040af WD |
418 | if (get_user(instr, (u16 __user *)pc)) |
419 | goto die_sig; | |
a79a0cb1 | 420 | instr = __mem_to_opcode_thumb16(instr); |
592201a9 JM |
421 | if (is_wide_instruction(instr)) { |
422 | unsigned int instr2; | |
2b2040af WD |
423 | if (get_user(instr2, (u16 __user *)pc+1)) |
424 | goto die_sig; | |
a79a0cb1 BD |
425 | instr2 = __mem_to_opcode_thumb16(instr2); |
426 | instr = __opcode_thumb32_compose(instr, instr2); | |
592201a9 | 427 | } |
2b2040af | 428 | } else if (get_user(instr, (u32 __user *)pc)) { |
a79a0cb1 | 429 | instr = __mem_to_opcode_arm(instr); |
2b2040af | 430 | goto die_sig; |
1da177e4 LT |
431 | } |
432 | ||
b03a5b75 RK |
433 | if (call_undef_hook(regs, instr) == 0) |
434 | return; | |
1da177e4 | 435 | |
2b2040af | 436 | die_sig: |
1da177e4 LT |
437 | #ifdef CONFIG_DEBUG_USER |
438 | if (user_debug & UDBG_UNDEFINED) { | |
439 | printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n", | |
19c5870c | 440 | current->comm, task_pid_nr(current), pc); |
e40c2ec6 | 441 | dump_instr(KERN_INFO, regs); |
1da177e4 LT |
442 | } |
443 | #endif | |
444 | ||
445 | info.si_signo = SIGILL; | |
446 | info.si_errno = 0; | |
447 | info.si_code = ILL_ILLOPC; | |
448 | info.si_addr = pc; | |
449 | ||
1eeb66a1 | 450 | arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6); |
1da177e4 LT |
451 | } |
452 | ||
453 | asmlinkage void do_unexp_fiq (struct pt_regs *regs) | |
454 | { | |
1da177e4 LT |
455 | printk("Hmm. Unexpected FIQ received, but trying to continue\n"); |
456 | printk("You may have a hardware problem...\n"); | |
1da177e4 LT |
457 | } |
458 | ||
459 | /* | |
460 | * bad_mode handles the impossible case in the vectors. If you see one of | |
461 | * these, then it's extremely serious, and could mean you have buggy hardware. | |
462 | * It never returns, and never tries to sync. We hope that we can at least | |
463 | * dump out some state information... | |
464 | */ | |
ae0a846e | 465 | asmlinkage void bad_mode(struct pt_regs *regs, int reason) |
1da177e4 LT |
466 | { |
467 | console_verbose(); | |
468 | ||
ae0a846e | 469 | printk(KERN_CRIT "Bad mode in %s handler detected\n", handler[reason]); |
1da177e4 LT |
470 | |
471 | die("Oops - bad mode", regs, 0); | |
472 | local_irq_disable(); | |
473 | panic("bad mode"); | |
474 | } | |
475 | ||
476 | static int bad_syscall(int n, struct pt_regs *regs) | |
477 | { | |
478 | struct thread_info *thread = current_thread_info(); | |
479 | siginfo_t info; | |
480 | ||
88b9ef45 | 481 | if ((current->personality & PER_MASK) != PER_LINUX && |
a999cb04 | 482 | thread->exec_domain->handler) { |
1da177e4 LT |
483 | thread->exec_domain->handler(n, regs); |
484 | return regs->ARM_r0; | |
485 | } | |
486 | ||
487 | #ifdef CONFIG_DEBUG_USER | |
488 | if (user_debug & UDBG_SYSCALL) { | |
489 | printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n", | |
19c5870c | 490 | task_pid_nr(current), current->comm, n); |
e40c2ec6 | 491 | dump_instr(KERN_ERR, regs); |
1da177e4 LT |
492 | } |
493 | #endif | |
494 | ||
495 | info.si_signo = SIGILL; | |
496 | info.si_errno = 0; | |
497 | info.si_code = ILL_ILLTRP; | |
498 | info.si_addr = (void __user *)instruction_pointer(regs) - | |
499 | (thumb_mode(regs) ? 2 : 4); | |
500 | ||
1eeb66a1 | 501 | arm_notify_die("Oops - bad syscall", regs, &info, n, 0); |
1da177e4 LT |
502 | |
503 | return regs->ARM_r0; | |
504 | } | |
505 | ||
28256d61 WD |
506 | static long do_cache_op_restart(struct restart_block *); |
507 | ||
c5102f59 | 508 | static inline int |
28256d61 WD |
509 | __do_cache_op(unsigned long start, unsigned long end) |
510 | { | |
511 | int ret; | |
28256d61 WD |
512 | |
513 | do { | |
b31459ad JM |
514 | unsigned long chunk = min(PAGE_SIZE, end - start); |
515 | ||
28256d61 WD |
516 | if (signal_pending(current)) { |
517 | struct thread_info *ti = current_thread_info(); | |
518 | ||
519 | ti->restart_block = (struct restart_block) { | |
520 | .fn = do_cache_op_restart, | |
521 | }; | |
522 | ||
523 | ti->arm_restart_block = (struct arm_restart_block) { | |
524 | { | |
525 | .cache = { | |
526 | .start = start, | |
527 | .end = end, | |
528 | }, | |
529 | }, | |
530 | }; | |
531 | ||
532 | return -ERESTART_RESTARTBLOCK; | |
533 | } | |
534 | ||
535 | ret = flush_cache_user_range(start, start + chunk); | |
536 | if (ret) | |
537 | return ret; | |
538 | ||
539 | cond_resched(); | |
540 | start += chunk; | |
541 | } while (start < end); | |
542 | ||
543 | return 0; | |
544 | } | |
545 | ||
546 | static long do_cache_op_restart(struct restart_block *unused) | |
1da177e4 | 547 | { |
28256d61 | 548 | struct arm_restart_block *restart_block; |
1da177e4 | 549 | |
28256d61 WD |
550 | restart_block = ¤t_thread_info()->arm_restart_block; |
551 | return __do_cache_op(restart_block->cache.start, | |
552 | restart_block->cache.end); | |
553 | } | |
554 | ||
c5102f59 | 555 | static inline int |
1da177e4 LT |
556 | do_cache_op(unsigned long start, unsigned long end, int flags) |
557 | { | |
1da177e4 | 558 | if (end < start || flags) |
c5102f59 | 559 | return -EINVAL; |
1da177e4 | 560 | |
97c72d89 WD |
561 | if (!access_ok(VERIFY_READ, start, end - start)) |
562 | return -EFAULT; | |
1da177e4 | 563 | |
28256d61 | 564 | return __do_cache_op(start, end); |
1da177e4 LT |
565 | } |
566 | ||
567 | /* | |
568 | * Handle all unrecognised system calls. | |
569 | * 0x9f0000 - 0x9fffff are some more esoteric system calls | |
570 | */ | |
571 | #define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE) | |
572 | asmlinkage int arm_syscall(int no, struct pt_regs *regs) | |
573 | { | |
574 | struct thread_info *thread = current_thread_info(); | |
575 | siginfo_t info; | |
576 | ||
3f2829a3 | 577 | if ((no >> 16) != (__ARM_NR_BASE>> 16)) |
1da177e4 LT |
578 | return bad_syscall(no, regs); |
579 | ||
580 | switch (no & 0xffff) { | |
581 | case 0: /* branch through 0 */ | |
582 | info.si_signo = SIGSEGV; | |
583 | info.si_errno = 0; | |
584 | info.si_code = SEGV_MAPERR; | |
585 | info.si_addr = NULL; | |
586 | ||
1eeb66a1 | 587 | arm_notify_die("branch through zero", regs, &info, 0, 0); |
1da177e4 LT |
588 | return 0; |
589 | ||
590 | case NR(breakpoint): /* SWI BREAK_POINT */ | |
591 | regs->ARM_pc -= thumb_mode(regs) ? 2 : 4; | |
592 | ptrace_break(current, regs); | |
593 | return regs->ARM_r0; | |
594 | ||
595 | /* | |
596 | * Flush a region from virtual address 'r0' to virtual address 'r1' | |
597 | * _exclusive_. There is no alignment requirement on either address; | |
598 | * user space does not need to know the hardware cache layout. | |
599 | * | |
600 | * r2 contains flags. It should ALWAYS be passed as ZERO until it | |
601 | * is defined to be something else. For now we ignore it, but may | |
602 | * the fires of hell burn in your belly if you break this rule. ;) | |
603 | * | |
604 | * (at a later date, we may want to allow this call to not flush | |
605 | * various aspects of the cache. Passing '0' will guarantee that | |
606 | * everything necessary gets flushed to maintain consistency in | |
607 | * the specified region). | |
608 | */ | |
609 | case NR(cacheflush): | |
c5102f59 | 610 | return do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2); |
1da177e4 LT |
611 | |
612 | case NR(usr26): | |
613 | if (!(elf_hwcap & HWCAP_26BIT)) | |
614 | break; | |
615 | regs->ARM_cpsr &= ~MODE32_BIT; | |
616 | return regs->ARM_r0; | |
617 | ||
618 | case NR(usr32): | |
619 | if (!(elf_hwcap & HWCAP_26BIT)) | |
620 | break; | |
621 | regs->ARM_cpsr |= MODE32_BIT; | |
622 | return regs->ARM_r0; | |
623 | ||
624 | case NR(set_tls): | |
a4780ade | 625 | thread->tp_value[0] = regs->ARM_r0; |
f159f4ed TL |
626 | if (tls_emu) |
627 | return 0; | |
628 | if (has_tls_reg) { | |
629 | asm ("mcr p15, 0, %0, c13, c0, 3" | |
630 | : : "r" (regs->ARM_r0)); | |
631 | } else { | |
632 | /* | |
633 | * User space must never try to access this directly. | |
634 | * Expect your app to break eventually if you do so. | |
635 | * The user helper at 0xffff0fe0 must be used instead. | |
636 | * (see entry-armv.S for details) | |
637 | */ | |
638 | *((unsigned int *)0xffff0ff0) = regs->ARM_r0; | |
639 | } | |
1da177e4 LT |
640 | return 0; |
641 | ||
dcef1f63 NP |
642 | #ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG |
643 | /* | |
644 | * Atomically store r1 in *r2 if *r2 is equal to r0 for user space. | |
645 | * Return zero in r0 if *MEM was changed or non-zero if no exchange | |
646 | * happened. Also set the user C flag accordingly. | |
647 | * If access permissions have to be fixed up then non-zero is | |
648 | * returned and the operation has to be re-attempted. | |
649 | * | |
650 | * *NOTE*: This is a ghost syscall private to the kernel. Only the | |
651 | * __kuser_cmpxchg code in entry-armv.S should be aware of its | |
652 | * existence. Don't ever use this from user code. | |
653 | */ | |
cc20d429 | 654 | case NR(cmpxchg): |
b49c0f24 | 655 | for (;;) { |
dcef1f63 NP |
656 | extern void do_DataAbort(unsigned long addr, unsigned int fsr, |
657 | struct pt_regs *regs); | |
658 | unsigned long val; | |
659 | unsigned long addr = regs->ARM_r2; | |
660 | struct mm_struct *mm = current->mm; | |
661 | pgd_t *pgd; pmd_t *pmd; pte_t *pte; | |
69b04754 | 662 | spinlock_t *ptl; |
dcef1f63 NP |
663 | |
664 | regs->ARM_cpsr &= ~PSR_C_BIT; | |
69b04754 | 665 | down_read(&mm->mmap_sem); |
dcef1f63 NP |
666 | pgd = pgd_offset(mm, addr); |
667 | if (!pgd_present(*pgd)) | |
668 | goto bad_access; | |
669 | pmd = pmd_offset(pgd, addr); | |
670 | if (!pmd_present(*pmd)) | |
671 | goto bad_access; | |
69b04754 | 672 | pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
373ce302 | 673 | if (!pte_present(*pte) || !pte_write(*pte) || !pte_dirty(*pte)) { |
69b04754 | 674 | pte_unmap_unlock(pte, ptl); |
dcef1f63 | 675 | goto bad_access; |
69b04754 | 676 | } |
dcef1f63 NP |
677 | val = *(unsigned long *)addr; |
678 | val -= regs->ARM_r0; | |
679 | if (val == 0) { | |
680 | *(unsigned long *)addr = regs->ARM_r1; | |
681 | regs->ARM_cpsr |= PSR_C_BIT; | |
682 | } | |
69b04754 HD |
683 | pte_unmap_unlock(pte, ptl); |
684 | up_read(&mm->mmap_sem); | |
dcef1f63 NP |
685 | return val; |
686 | ||
687 | bad_access: | |
69b04754 | 688 | up_read(&mm->mmap_sem); |
74f88494 | 689 | /* simulate a write access fault */ |
dcef1f63 | 690 | do_DataAbort(addr, 15 + (1 << 11), regs); |
dcef1f63 NP |
691 | } |
692 | #endif | |
693 | ||
1da177e4 LT |
694 | default: |
695 | /* Calls 9f00xx..9f07ff are defined to return -ENOSYS | |
696 | if not implemented, rather than raising SIGILL. This | |
697 | way the calling program can gracefully determine whether | |
698 | a feature is supported. */ | |
bfd2e29f | 699 | if ((no & 0xffff) <= 0x7ff) |
1da177e4 LT |
700 | return -ENOSYS; |
701 | break; | |
702 | } | |
703 | #ifdef CONFIG_DEBUG_USER | |
704 | /* | |
705 | * experience shows that these seem to indicate that | |
706 | * something catastrophic has happened | |
707 | */ | |
708 | if (user_debug & UDBG_SYSCALL) { | |
709 | printk("[%d] %s: arm syscall %d\n", | |
19c5870c | 710 | task_pid_nr(current), current->comm, no); |
e40c2ec6 | 711 | dump_instr("", regs); |
1da177e4 | 712 | if (user_mode(regs)) { |
652a12ef | 713 | __show_regs(regs); |
1da177e4 LT |
714 | c_backtrace(regs->ARM_fp, processor_mode(regs)); |
715 | } | |
716 | } | |
717 | #endif | |
718 | info.si_signo = SIGILL; | |
719 | info.si_errno = 0; | |
720 | info.si_code = ILL_ILLTRP; | |
721 | info.si_addr = (void __user *)instruction_pointer(regs) - | |
722 | (thumb_mode(regs) ? 2 : 4); | |
723 | ||
1eeb66a1 | 724 | arm_notify_die("Oops - bad syscall(2)", regs, &info, no, 0); |
1da177e4 LT |
725 | return 0; |
726 | } | |
727 | ||
4b0e07a5 | 728 | #ifdef CONFIG_TLS_REG_EMUL |
2d2669b6 NP |
729 | |
730 | /* | |
731 | * We might be running on an ARMv6+ processor which should have the TLS | |
4b0e07a5 NP |
732 | * register but for some reason we can't use it, or maybe an SMP system |
733 | * using a pre-ARMv6 processor (there are apparently a few prototypes like | |
734 | * that in existence) and therefore access to that register must be | |
735 | * emulated. | |
2d2669b6 NP |
736 | */ |
737 | ||
738 | static int get_tp_trap(struct pt_regs *regs, unsigned int instr) | |
739 | { | |
740 | int reg = (instr >> 12) & 15; | |
741 | if (reg == 15) | |
742 | return 1; | |
a4780ade | 743 | regs->uregs[reg] = current_thread_info()->tp_value[0]; |
2d2669b6 NP |
744 | regs->ARM_pc += 4; |
745 | return 0; | |
746 | } | |
747 | ||
748 | static struct undef_hook arm_mrc_hook = { | |
749 | .instr_mask = 0x0fff0fff, | |
750 | .instr_val = 0x0e1d0f70, | |
751 | .cpsr_mask = PSR_T_BIT, | |
752 | .cpsr_val = 0, | |
753 | .fn = get_tp_trap, | |
754 | }; | |
755 | ||
756 | static int __init arm_mrc_hook_init(void) | |
757 | { | |
758 | register_undef_hook(&arm_mrc_hook); | |
759 | return 0; | |
760 | } | |
761 | ||
762 | late_initcall(arm_mrc_hook_init); | |
763 | ||
764 | #endif | |
765 | ||
1da177e4 LT |
766 | void __bad_xchg(volatile void *ptr, int size) |
767 | { | |
768 | printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n", | |
769 | __builtin_return_address(0), ptr, size); | |
770 | BUG(); | |
771 | } | |
772 | EXPORT_SYMBOL(__bad_xchg); | |
773 | ||
774 | /* | |
775 | * A data abort trap was taken, but we did not handle the instruction. | |
776 | * Try to abort the user program, or panic if it was the kernel. | |
777 | */ | |
778 | asmlinkage void | |
779 | baddataabort(int code, unsigned long instr, struct pt_regs *regs) | |
780 | { | |
781 | unsigned long addr = instruction_pointer(regs); | |
782 | siginfo_t info; | |
783 | ||
784 | #ifdef CONFIG_DEBUG_USER | |
785 | if (user_debug & UDBG_BADABORT) { | |
786 | printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n", | |
19c5870c | 787 | task_pid_nr(current), current->comm, code, instr); |
e40c2ec6 | 788 | dump_instr(KERN_ERR, regs); |
1da177e4 LT |
789 | show_pte(current->mm, addr); |
790 | } | |
791 | #endif | |
792 | ||
793 | info.si_signo = SIGILL; | |
794 | info.si_errno = 0; | |
795 | info.si_code = ILL_ILLOPC; | |
796 | info.si_addr = (void __user *)addr; | |
797 | ||
1eeb66a1 | 798 | arm_notify_die("unknown data abort code", regs, &info, instr, 0); |
1da177e4 LT |
799 | } |
800 | ||
1da177e4 LT |
801 | void __readwrite_bug(const char *fn) |
802 | { | |
803 | printk("%s called, but not implemented\n", fn); | |
804 | BUG(); | |
805 | } | |
806 | EXPORT_SYMBOL(__readwrite_bug); | |
807 | ||
69529c0e | 808 | void __pte_error(const char *file, int line, pte_t pte) |
1da177e4 | 809 | { |
29a38193 | 810 | printk("%s:%d: bad pte %08llx.\n", file, line, (long long)pte_val(pte)); |
1da177e4 LT |
811 | } |
812 | ||
69529c0e | 813 | void __pmd_error(const char *file, int line, pmd_t pmd) |
1da177e4 | 814 | { |
29a38193 | 815 | printk("%s:%d: bad pmd %08llx.\n", file, line, (long long)pmd_val(pmd)); |
1da177e4 LT |
816 | } |
817 | ||
69529c0e | 818 | void __pgd_error(const char *file, int line, pgd_t pgd) |
1da177e4 | 819 | { |
29a38193 | 820 | printk("%s:%d: bad pgd %08llx.\n", file, line, (long long)pgd_val(pgd)); |
1da177e4 LT |
821 | } |
822 | ||
823 | asmlinkage void __div0(void) | |
824 | { | |
825 | printk("Division by zero in kernel.\n"); | |
826 | dump_stack(); | |
827 | } | |
828 | EXPORT_SYMBOL(__div0); | |
829 | ||
830 | void abort(void) | |
831 | { | |
832 | BUG(); | |
833 | ||
834 | /* if that doesn't kill us, halt */ | |
835 | panic("Oops failed to kill thread"); | |
836 | } | |
837 | EXPORT_SYMBOL(abort); | |
838 | ||
839 | void __init trap_init(void) | |
5cbad0eb JW |
840 | { |
841 | return; | |
842 | } | |
843 | ||
f6f91b0d RK |
844 | #ifdef CONFIG_KUSER_HELPERS |
845 | static void __init kuser_init(void *vectors) | |
f159f4ed | 846 | { |
f6f91b0d RK |
847 | extern char __kuser_helper_start[], __kuser_helper_end[]; |
848 | int kuser_sz = __kuser_helper_end - __kuser_helper_start; | |
849 | ||
850 | memcpy(vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz); | |
851 | ||
f159f4ed TL |
852 | /* |
853 | * vectors + 0xfe0 = __kuser_get_tls | |
854 | * vectors + 0xfe8 = hardware TLS instruction at 0xffff0fe8 | |
855 | */ | |
856 | if (tls_emu || has_tls_reg) | |
f6f91b0d RK |
857 | memcpy(vectors + 0xfe0, vectors + 0xfe8, 4); |
858 | } | |
859 | #else | |
5761704a | 860 | static inline void __init kuser_init(void *vectors) |
f6f91b0d | 861 | { |
f159f4ed | 862 | } |
f6f91b0d | 863 | #endif |
f159f4ed | 864 | |
94e5a85b | 865 | void __init early_trap_init(void *vectors_base) |
1da177e4 | 866 | { |
55bdd694 | 867 | #ifndef CONFIG_CPU_V7M |
94e5a85b | 868 | unsigned long vectors = (unsigned long)vectors_base; |
7933523d RK |
869 | extern char __stubs_start[], __stubs_end[]; |
870 | extern char __vectors_start[], __vectors_end[]; | |
f928d4f2 | 871 | unsigned i; |
1da177e4 | 872 | |
94e5a85b RK |
873 | vectors_page = vectors_base; |
874 | ||
f928d4f2 RK |
875 | /* |
876 | * Poison the vectors page with an undefined instruction. This | |
877 | * instruction is chosen to be undefined for both ARM and Thumb | |
878 | * ISAs. The Thumb version is an undefined instruction with a | |
879 | * branch back to the undefined instruction. | |
880 | */ | |
881 | for (i = 0; i < PAGE_SIZE / sizeof(u32); i++) | |
882 | ((u32 *)vectors_base)[i] = 0xe7fddef1; | |
883 | ||
7933523d | 884 | /* |
2d2669b6 NP |
885 | * Copy the vectors, stubs and kuser helpers (in entry-armv.S) |
886 | * into the vector page, mapped at 0xffff0000, and ensure these | |
887 | * are visible to the instruction stream. | |
7933523d | 888 | */ |
c760fc19 | 889 | memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start); |
19accfd3 | 890 | memcpy((void *)vectors + 0x1000, __stubs_start, __stubs_end - __stubs_start); |
e00d349e | 891 | |
f6f91b0d | 892 | kuser_init(vectors_base); |
f159f4ed | 893 | |
19accfd3 | 894 | flush_icache_range(vectors, vectors + PAGE_SIZE * 2); |
1da177e4 | 895 | modify_domain(DOMAIN_USER, DOMAIN_CLIENT); |
55bdd694 CM |
896 | #else /* ifndef CONFIG_CPU_V7M */ |
897 | /* | |
898 | * on V7-M there is no need to copy the vector table to a dedicated | |
899 | * memory area. The address is configurable and so a table in the kernel | |
900 | * image can be used. | |
901 | */ | |
902 | #endif | |
1da177e4 | 903 | } |