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 | 21 | #include <linux/kdebug.h> |
eb0146da | 22 | #include <linux/kprobes.h> |
a9221de6 RK |
23 | #include <linux/module.h> |
24 | #include <linux/kexec.h> | |
87e040b6 | 25 | #include <linux/bug.h> |
a9221de6 | 26 | #include <linux/delay.h> |
1da177e4 | 27 | #include <linux/init.h> |
3f07c014 | 28 | #include <linux/sched/signal.h> |
b17b0153 | 29 | #include <linux/sched/debug.h> |
68db0cf1 | 30 | #include <linux/sched/task_stack.h> |
c0e7f7ee | 31 | #include <linux/irq.h> |
1da177e4 | 32 | |
60063497 | 33 | #include <linux/atomic.h> |
1da177e4 | 34 | #include <asm/cacheflush.h> |
5a567d78 | 35 | #include <asm/exception.h> |
1da177e4 LT |
36 | #include <asm/unistd.h> |
37 | #include <asm/traps.h> | |
49432d4a | 38 | #include <asm/ptrace.h> |
bff595c1 | 39 | #include <asm/unwind.h> |
f159f4ed | 40 | #include <asm/tls.h> |
9f97da78 | 41 | #include <asm/system_misc.h> |
a79a0cb1 | 42 | #include <asm/opcodes.h> |
1da177e4 | 43 | |
49432d4a | 44 | |
29c350bf RK |
45 | static const char *handler[]= { |
46 | "prefetch abort", | |
47 | "data abort", | |
48 | "address exception", | |
49 | "interrupt", | |
50 | "undefined instruction", | |
51 | }; | |
1da177e4 | 52 | |
247055aa CM |
53 | void *vectors_page; |
54 | ||
1da177e4 LT |
55 | #ifdef CONFIG_DEBUG_USER |
56 | unsigned int user_debug; | |
57 | ||
58 | static int __init user_debug_setup(char *str) | |
59 | { | |
60 | get_option(&str, &user_debug); | |
61 | return 1; | |
62 | } | |
63 | __setup("user_debug=", user_debug_setup); | |
64 | #endif | |
65 | ||
e40c2ec6 | 66 | static void dump_mem(const char *, const char *, unsigned long, unsigned long); |
7ab3f8d5 | 67 | |
7ab3f8d5 | 68 | void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame) |
1da177e4 LT |
69 | { |
70 | #ifdef CONFIG_KALLSYMS | |
ef41b5c9 | 71 | printk("[<%08lx>] (%ps) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from); |
1da177e4 LT |
72 | #else |
73 | printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from); | |
74 | #endif | |
7ab3f8d5 | 75 | |
c6089061 | 76 | if (in_entry_text(from)) |
e40c2ec6 | 77 | dump_mem("", "Exception stack", frame + 4, frame + 4 + sizeof(struct pt_regs)); |
1da177e4 LT |
78 | } |
79 | ||
24c66dfd RK |
80 | void dump_backtrace_stm(u32 *stack, u32 instruction) |
81 | { | |
82 | char str[80], *p; | |
83 | unsigned int x; | |
84 | int reg; | |
85 | ||
86 | for (reg = 10, x = 0, p = str; reg >= 0; reg--) { | |
87 | if (instruction & BIT(reg)) { | |
88 | p += sprintf(p, " r%d:%08x", reg, *stack--); | |
89 | if (++x == 6) { | |
90 | x = 0; | |
91 | p = str; | |
92 | printk("%s\n", str); | |
93 | } | |
94 | } | |
95 | } | |
96 | if (p != str) | |
97 | printk("%s\n", str); | |
98 | } | |
99 | ||
bff595c1 | 100 | #ifndef CONFIG_ARM_UNWIND |
1da177e4 LT |
101 | /* |
102 | * Stack pointers should always be within the kernels view of | |
103 | * physical memory. If it is not there, then we can't dump | |
104 | * out any information relating to the stack. | |
105 | */ | |
106 | static int verify_stack(unsigned long sp) | |
107 | { | |
09d9bae0 RK |
108 | if (sp < PAGE_OFFSET || |
109 | (sp > (unsigned long)high_memory && high_memory != NULL)) | |
1da177e4 LT |
110 | return -EFAULT; |
111 | ||
112 | return 0; | |
113 | } | |
bff595c1 | 114 | #endif |
1da177e4 LT |
115 | |
116 | /* | |
117 | * Dump out the contents of some memory nicely... | |
118 | */ | |
e40c2ec6 RK |
119 | static void dump_mem(const char *lvl, const char *str, unsigned long bottom, |
120 | unsigned long top) | |
1da177e4 | 121 | { |
d191fe09 | 122 | unsigned long first; |
1da177e4 LT |
123 | mm_segment_t fs; |
124 | int i; | |
125 | ||
126 | /* | |
127 | * We need to switch to kernel mode so that we can use __get_user | |
128 | * to safely read from kernel space. Note that we now dump the | |
129 | * code first, just in case the backtrace kills us. | |
130 | */ | |
131 | fs = get_fs(); | |
132 | set_fs(KERNEL_DS); | |
133 | ||
e40c2ec6 | 134 | printk("%s%s(0x%08lx to 0x%08lx)\n", lvl, str, bottom, top); |
1da177e4 | 135 | |
d191fe09 RK |
136 | for (first = bottom & ~31; first < top; first += 32) { |
137 | unsigned long p; | |
138 | char str[sizeof(" 12345678") * 8 + 1]; | |
1da177e4 | 139 | |
d191fe09 RK |
140 | memset(str, ' ', sizeof(str)); |
141 | str[sizeof(str) - 1] = '\0'; | |
1da177e4 | 142 | |
d191fe09 RK |
143 | for (p = first, i = 0; i < 8 && p < top; i++, p += 4) { |
144 | if (p >= bottom && p < top) { | |
145 | unsigned long val; | |
146 | if (__get_user(val, (unsigned long *)p) == 0) | |
147 | sprintf(str + i * 9, " %08lx", val); | |
148 | else | |
149 | sprintf(str + i * 9, " ????????"); | |
1da177e4 LT |
150 | } |
151 | } | |
e40c2ec6 | 152 | printk("%s%04lx:%s\n", lvl, first & 0xffff, str); |
1da177e4 LT |
153 | } |
154 | ||
155 | set_fs(fs); | |
156 | } | |
157 | ||
b9dd05c7 | 158 | static void __dump_instr(const char *lvl, struct pt_regs *regs) |
1da177e4 LT |
159 | { |
160 | unsigned long addr = instruction_pointer(regs); | |
161 | const int thumb = thumb_mode(regs); | |
162 | const int width = thumb ? 4 : 8; | |
d191fe09 | 163 | char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str; |
1da177e4 LT |
164 | int i; |
165 | ||
166 | /* | |
b9dd05c7 MR |
167 | * Note that we now dump the code first, just in case the backtrace |
168 | * kills us. | |
1da177e4 | 169 | */ |
1da177e4 | 170 | |
a9011580 | 171 | for (i = -4; i < 1 + !!thumb; i++) { |
1da177e4 LT |
172 | unsigned int val, bad; |
173 | ||
174 | if (thumb) | |
b9dd05c7 | 175 | bad = get_user(val, &((u16 *)addr)[i]); |
1da177e4 | 176 | else |
b9dd05c7 | 177 | bad = get_user(val, &((u32 *)addr)[i]); |
1da177e4 LT |
178 | |
179 | if (!bad) | |
d191fe09 RK |
180 | p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ", |
181 | width, val); | |
1da177e4 | 182 | else { |
d191fe09 | 183 | p += sprintf(p, "bad PC value"); |
1da177e4 LT |
184 | break; |
185 | } | |
186 | } | |
e40c2ec6 | 187 | printk("%sCode: %s\n", lvl, str); |
b9dd05c7 | 188 | } |
1da177e4 | 189 | |
b9dd05c7 MR |
190 | static void dump_instr(const char *lvl, struct pt_regs *regs) |
191 | { | |
192 | mm_segment_t fs; | |
193 | ||
194 | if (!user_mode(regs)) { | |
195 | fs = get_fs(); | |
196 | set_fs(KERNEL_DS); | |
197 | __dump_instr(lvl, regs); | |
198 | set_fs(fs); | |
199 | } else { | |
200 | __dump_instr(lvl, regs); | |
201 | } | |
1da177e4 LT |
202 | } |
203 | ||
bff595c1 CM |
204 | #ifdef CONFIG_ARM_UNWIND |
205 | static inline void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) | |
206 | { | |
207 | unwind_backtrace(regs, tsk); | |
208 | } | |
209 | #else | |
1da177e4 LT |
210 | static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) |
211 | { | |
67a94c23 | 212 | unsigned int fp, mode; |
1da177e4 LT |
213 | int ok = 1; |
214 | ||
215 | printk("Backtrace: "); | |
67a94c23 CM |
216 | |
217 | if (!tsk) | |
218 | tsk = current; | |
219 | ||
220 | if (regs) { | |
49432d4a | 221 | fp = frame_pointer(regs); |
67a94c23 CM |
222 | mode = processor_mode(regs); |
223 | } else if (tsk != current) { | |
224 | fp = thread_saved_fp(tsk); | |
225 | mode = 0x10; | |
226 | } else { | |
227 | asm("mov %0, fp" : "=r" (fp) : : "cc"); | |
228 | mode = 0x10; | |
229 | } | |
230 | ||
1da177e4 | 231 | if (!fp) { |
4ed89f22 | 232 | pr_cont("no frame pointer"); |
1da177e4 LT |
233 | ok = 0; |
234 | } else if (verify_stack(fp)) { | |
4ed89f22 | 235 | pr_cont("invalid frame pointer 0x%08x", fp); |
1da177e4 | 236 | ok = 0; |
55205823 | 237 | } else if (fp < (unsigned long)end_of_stack(tsk)) |
4ed89f22 RK |
238 | pr_cont("frame pointer underflow"); |
239 | pr_cont("\n"); | |
1da177e4 LT |
240 | |
241 | if (ok) | |
67a94c23 | 242 | c_backtrace(fp, mode); |
1da177e4 | 243 | } |
bff595c1 | 244 | #endif |
1da177e4 | 245 | |
1da177e4 LT |
246 | void show_stack(struct task_struct *tsk, unsigned long *sp) |
247 | { | |
67a94c23 | 248 | dump_backtrace(NULL, tsk); |
1da177e4 LT |
249 | barrier(); |
250 | } | |
251 | ||
d9202429 RK |
252 | #ifdef CONFIG_PREEMPT |
253 | #define S_PREEMPT " PREEMPT" | |
254 | #else | |
255 | #define S_PREEMPT "" | |
256 | #endif | |
257 | #ifdef CONFIG_SMP | |
258 | #define S_SMP " SMP" | |
259 | #else | |
260 | #define S_SMP "" | |
261 | #endif | |
8211ca65 RK |
262 | #ifdef CONFIG_THUMB2_KERNEL |
263 | #define S_ISA " THUMB2" | |
264 | #else | |
265 | #define S_ISA " ARM" | |
266 | #endif | |
d9202429 | 267 | |
02df19b4 | 268 | static int __die(const char *str, int err, struct pt_regs *regs) |
1da177e4 | 269 | { |
02df19b4 | 270 | struct task_struct *tsk = current; |
1da177e4 | 271 | static int die_counter; |
a9221de6 | 272 | int ret; |
1da177e4 | 273 | |
4ed89f22 RK |
274 | pr_emerg("Internal error: %s: %x [#%d]" S_PREEMPT S_SMP S_ISA "\n", |
275 | str, err, ++die_counter); | |
a9221de6 RK |
276 | |
277 | /* trap and error numbers are mostly meaningless on ARM */ | |
278 | ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, SIGSEGV); | |
279 | if (ret == NOTIFY_STOP) | |
02df19b4 | 280 | return 1; |
a9221de6 | 281 | |
1da177e4 | 282 | print_modules(); |
652a12ef | 283 | __show_regs(regs); |
4ed89f22 RK |
284 | pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n", |
285 | TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), end_of_stack(tsk)); | |
1da177e4 LT |
286 | |
287 | if (!user_mode(regs) || in_interrupt()) { | |
e40c2ec6 | 288 | dump_mem(KERN_EMERG, "Stack: ", regs->ARM_sp, |
32d39a93 | 289 | THREAD_SIZE + (unsigned long)task_stack_page(tsk)); |
1da177e4 | 290 | dump_backtrace(regs, tsk); |
e40c2ec6 | 291 | dump_instr(KERN_EMERG, regs); |
1da177e4 | 292 | } |
a9221de6 | 293 | |
02df19b4 | 294 | return 0; |
d362979a | 295 | } |
1da177e4 | 296 | |
02df19b4 RV |
297 | static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED; |
298 | static int die_owner = -1; | |
299 | static unsigned int die_nest_count; | |
d362979a | 300 | |
02df19b4 | 301 | static unsigned long oops_begin(void) |
d362979a | 302 | { |
02df19b4 RV |
303 | int cpu; |
304 | unsigned long flags; | |
d362979a | 305 | |
d9202429 RK |
306 | oops_enter(); |
307 | ||
02df19b4 RV |
308 | /* racy, but better than risking deadlock. */ |
309 | raw_local_irq_save(flags); | |
310 | cpu = smp_processor_id(); | |
311 | if (!arch_spin_trylock(&die_lock)) { | |
312 | if (cpu == die_owner) | |
313 | /* nested oops. should stop eventually */; | |
314 | else | |
315 | arch_spin_lock(&die_lock); | |
316 | } | |
317 | die_nest_count++; | |
318 | die_owner = cpu; | |
03a6e5bd | 319 | console_verbose(); |
d362979a | 320 | bust_spinlocks(1); |
02df19b4 RV |
321 | return flags; |
322 | } | |
a9221de6 | 323 | |
02df19b4 RV |
324 | static void oops_end(unsigned long flags, struct pt_regs *regs, int signr) |
325 | { | |
326 | if (regs && kexec_should_crash(current)) | |
a9221de6 RK |
327 | crash_kexec(regs); |
328 | ||
1da177e4 | 329 | bust_spinlocks(0); |
02df19b4 | 330 | die_owner = -1; |
373d4d09 | 331 | add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); |
02df19b4 RV |
332 | die_nest_count--; |
333 | if (!die_nest_count) | |
334 | /* Nest count reaches zero, release the lock. */ | |
335 | arch_spin_unlock(&die_lock); | |
336 | raw_local_irq_restore(flags); | |
03a6e5bd | 337 | oops_exit(); |
31867499 | 338 | |
d9202429 RK |
339 | if (in_interrupt()) |
340 | panic("Fatal exception in interrupt"); | |
cea6a4ba | 341 | if (panic_on_oops) |
012c437d | 342 | panic("Fatal exception"); |
02df19b4 RV |
343 | if (signr) |
344 | do_exit(signr); | |
345 | } | |
346 | ||
347 | /* | |
348 | * This function is protected against re-entrancy. | |
349 | */ | |
350 | void die(const char *str, struct pt_regs *regs, int err) | |
351 | { | |
352 | enum bug_trap_type bug_type = BUG_TRAP_TYPE_NONE; | |
353 | unsigned long flags = oops_begin(); | |
354 | int sig = SIGSEGV; | |
355 | ||
356 | if (!user_mode(regs)) | |
357 | bug_type = report_bug(regs->ARM_pc, regs); | |
358 | if (bug_type != BUG_TRAP_TYPE_NONE) | |
359 | str = "Oops - BUG"; | |
360 | ||
361 | if (__die(str, err, regs)) | |
362 | sig = 0; | |
363 | ||
364 | oops_end(flags, regs, sig); | |
1da177e4 LT |
365 | } |
366 | ||
1eeb66a1 | 367 | void arm_notify_die(const char *str, struct pt_regs *regs, |
05e792e3 EB |
368 | int signo, int si_code, void __user *addr, |
369 | unsigned long err, unsigned long trap) | |
1da177e4 LT |
370 | { |
371 | if (user_mode(regs)) { | |
372 | current->thread.error_code = err; | |
373 | current->thread.trap_no = trap; | |
374 | ||
05e792e3 | 375 | force_sig_fault(signo, si_code, addr, current); |
1da177e4 LT |
376 | } else { |
377 | die(str, regs, err); | |
378 | } | |
379 | } | |
380 | ||
87e040b6 SG |
381 | #ifdef CONFIG_GENERIC_BUG |
382 | ||
383 | int is_valid_bugaddr(unsigned long pc) | |
384 | { | |
385 | #ifdef CONFIG_THUMB2_KERNEL | |
63328070 BD |
386 | u16 bkpt; |
387 | u16 insn = __opcode_to_mem_thumb16(BUG_INSTR_VALUE); | |
87e040b6 | 388 | #else |
63328070 BD |
389 | u32 bkpt; |
390 | u32 insn = __opcode_to_mem_arm(BUG_INSTR_VALUE); | |
87e040b6 SG |
391 | #endif |
392 | ||
393 | if (probe_kernel_address((unsigned *)pc, bkpt)) | |
394 | return 0; | |
395 | ||
63328070 | 396 | return bkpt == insn; |
87e040b6 SG |
397 | } |
398 | ||
399 | #endif | |
400 | ||
1da177e4 | 401 | static LIST_HEAD(undef_hook); |
bd31b859 | 402 | static DEFINE_RAW_SPINLOCK(undef_lock); |
1da177e4 LT |
403 | |
404 | void register_undef_hook(struct undef_hook *hook) | |
405 | { | |
109d89ca RK |
406 | unsigned long flags; |
407 | ||
bd31b859 | 408 | raw_spin_lock_irqsave(&undef_lock, flags); |
1da177e4 | 409 | list_add(&hook->node, &undef_hook); |
bd31b859 | 410 | raw_spin_unlock_irqrestore(&undef_lock, flags); |
1da177e4 LT |
411 | } |
412 | ||
413 | void unregister_undef_hook(struct undef_hook *hook) | |
414 | { | |
109d89ca RK |
415 | unsigned long flags; |
416 | ||
bd31b859 | 417 | raw_spin_lock_irqsave(&undef_lock, flags); |
1da177e4 | 418 | list_del(&hook->node); |
bd31b859 | 419 | raw_spin_unlock_irqrestore(&undef_lock, flags); |
1da177e4 LT |
420 | } |
421 | ||
eb0146da MH |
422 | static nokprobe_inline |
423 | int call_undef_hook(struct pt_regs *regs, unsigned int instr) | |
b03a5b75 RK |
424 | { |
425 | struct undef_hook *hook; | |
426 | unsigned long flags; | |
427 | int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL; | |
428 | ||
bd31b859 | 429 | raw_spin_lock_irqsave(&undef_lock, flags); |
b03a5b75 RK |
430 | list_for_each_entry(hook, &undef_hook, node) |
431 | if ((instr & hook->instr_mask) == hook->instr_val && | |
432 | (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val) | |
433 | fn = hook->fn; | |
bd31b859 | 434 | raw_spin_unlock_irqrestore(&undef_lock, flags); |
b03a5b75 RK |
435 | |
436 | return fn ? fn(regs, instr) : 1; | |
437 | } | |
438 | ||
c6089061 | 439 | asmlinkage void do_undefinstr(struct pt_regs *regs) |
1da177e4 | 440 | { |
1da177e4 | 441 | unsigned int instr; |
1da177e4 LT |
442 | void __user *pc; |
443 | ||
1da177e4 | 444 | pc = (void __user *)instruction_pointer(regs); |
dfc544c7 DW |
445 | |
446 | if (processor_mode(regs) == SVC_MODE) { | |
592201a9 JM |
447 | #ifdef CONFIG_THUMB2_KERNEL |
448 | if (thumb_mode(regs)) { | |
a79a0cb1 | 449 | instr = __mem_to_opcode_thumb16(((u16 *)pc)[0]); |
592201a9 | 450 | if (is_wide_instruction(instr)) { |
a79a0cb1 BD |
451 | u16 inst2; |
452 | inst2 = __mem_to_opcode_thumb16(((u16 *)pc)[1]); | |
453 | instr = __opcode_thumb32_compose(instr, inst2); | |
592201a9 JM |
454 | } |
455 | } else | |
456 | #endif | |
a79a0cb1 | 457 | instr = __mem_to_opcode_arm(*(u32 *) pc); |
dfc544c7 | 458 | } else if (thumb_mode(regs)) { |
2b2040af WD |
459 | if (get_user(instr, (u16 __user *)pc)) |
460 | goto die_sig; | |
a79a0cb1 | 461 | instr = __mem_to_opcode_thumb16(instr); |
592201a9 JM |
462 | if (is_wide_instruction(instr)) { |
463 | unsigned int instr2; | |
2b2040af WD |
464 | if (get_user(instr2, (u16 __user *)pc+1)) |
465 | goto die_sig; | |
a79a0cb1 BD |
466 | instr2 = __mem_to_opcode_thumb16(instr2); |
467 | instr = __opcode_thumb32_compose(instr, instr2); | |
592201a9 | 468 | } |
d6cd9894 TK |
469 | } else { |
470 | if (get_user(instr, (u32 __user *)pc)) | |
471 | goto die_sig; | |
a79a0cb1 | 472 | instr = __mem_to_opcode_arm(instr); |
1da177e4 LT |
473 | } |
474 | ||
b03a5b75 RK |
475 | if (call_undef_hook(regs, instr) == 0) |
476 | return; | |
1da177e4 | 477 | |
2b2040af | 478 | die_sig: |
1da177e4 LT |
479 | #ifdef CONFIG_DEBUG_USER |
480 | if (user_debug & UDBG_UNDEFINED) { | |
4ed89f22 | 481 | pr_info("%s (%d): undefined instruction: pc=%p\n", |
19c5870c | 482 | current->comm, task_pid_nr(current), pc); |
b5b6b5f5 | 483 | __show_regs(regs); |
e40c2ec6 | 484 | dump_instr(KERN_INFO, regs); |
1da177e4 LT |
485 | } |
486 | #endif | |
05e792e3 EB |
487 | arm_notify_die("Oops - undefined instruction", regs, |
488 | SIGILL, ILL_ILLOPC, pc, 0, 6); | |
1da177e4 | 489 | } |
eb0146da | 490 | NOKPROBE_SYMBOL(do_undefinstr) |
1da177e4 | 491 | |
c0e7f7ee DT |
492 | /* |
493 | * Handle FIQ similarly to NMI on x86 systems. | |
494 | * | |
495 | * The runtime environment for NMIs is extremely restrictive | |
496 | * (NMIs can pre-empt critical sections meaning almost all locking is | |
497 | * forbidden) meaning this default FIQ handling must only be used in | |
498 | * circumstances where non-maskability improves robustness, such as | |
499 | * watchdog or debug logic. | |
500 | * | |
501 | * This handler is not appropriate for general purpose use in drivers | |
502 | * platform code and can be overrideen using set_fiq_handler. | |
503 | */ | |
504 | asmlinkage void __exception_irq_entry handle_fiq_as_nmi(struct pt_regs *regs) | |
505 | { | |
506 | struct pt_regs *old_regs = set_irq_regs(regs); | |
507 | ||
508 | nmi_enter(); | |
509 | ||
510 | /* nop. FIQ handlers for special arch/arm features can be added here. */ | |
511 | ||
512 | nmi_exit(); | |
513 | ||
514 | set_irq_regs(old_regs); | |
515 | } | |
516 | ||
1da177e4 LT |
517 | /* |
518 | * bad_mode handles the impossible case in the vectors. If you see one of | |
519 | * these, then it's extremely serious, and could mean you have buggy hardware. | |
520 | * It never returns, and never tries to sync. We hope that we can at least | |
521 | * dump out some state information... | |
522 | */ | |
ae0a846e | 523 | asmlinkage void bad_mode(struct pt_regs *regs, int reason) |
1da177e4 LT |
524 | { |
525 | console_verbose(); | |
526 | ||
4ed89f22 | 527 | pr_crit("Bad mode in %s handler detected\n", handler[reason]); |
1da177e4 LT |
528 | |
529 | die("Oops - bad mode", regs, 0); | |
530 | local_irq_disable(); | |
531 | panic("bad mode"); | |
532 | } | |
533 | ||
534 | static int bad_syscall(int n, struct pt_regs *regs) | |
535 | { | |
a4980448 RW |
536 | if ((current->personality & PER_MASK) != PER_LINUX) { |
537 | send_sig(SIGSEGV, current, 1); | |
1da177e4 LT |
538 | return regs->ARM_r0; |
539 | } | |
540 | ||
541 | #ifdef CONFIG_DEBUG_USER | |
542 | if (user_debug & UDBG_SYSCALL) { | |
4ed89f22 | 543 | pr_err("[%d] %s: obsolete system call %08x.\n", |
19c5870c | 544 | task_pid_nr(current), current->comm, n); |
e40c2ec6 | 545 | dump_instr(KERN_ERR, regs); |
1da177e4 LT |
546 | } |
547 | #endif | |
548 | ||
05e792e3 EB |
549 | arm_notify_die("Oops - bad syscall", regs, SIGILL, ILL_ILLTRP, |
550 | (void __user *)instruction_pointer(regs) - | |
551 | (thumb_mode(regs) ? 2 : 4), | |
552 | n, 0); | |
1da177e4 LT |
553 | |
554 | return regs->ARM_r0; | |
555 | } | |
556 | ||
c5102f59 | 557 | static inline int |
28256d61 WD |
558 | __do_cache_op(unsigned long start, unsigned long end) |
559 | { | |
560 | int ret; | |
28256d61 WD |
561 | |
562 | do { | |
b31459ad JM |
563 | unsigned long chunk = min(PAGE_SIZE, end - start); |
564 | ||
3f4aa45c VM |
565 | if (fatal_signal_pending(current)) |
566 | return 0; | |
28256d61 WD |
567 | |
568 | ret = flush_cache_user_range(start, start + chunk); | |
569 | if (ret) | |
570 | return ret; | |
571 | ||
572 | cond_resched(); | |
573 | start += chunk; | |
574 | } while (start < end); | |
575 | ||
576 | return 0; | |
577 | } | |
578 | ||
c5102f59 | 579 | static inline int |
1da177e4 LT |
580 | do_cache_op(unsigned long start, unsigned long end, int flags) |
581 | { | |
1da177e4 | 582 | if (end < start || flags) |
c5102f59 | 583 | return -EINVAL; |
1da177e4 | 584 | |
96d4f267 | 585 | if (!access_ok(start, end - start)) |
97c72d89 | 586 | return -EFAULT; |
1da177e4 | 587 | |
28256d61 | 588 | return __do_cache_op(start, end); |
1da177e4 LT |
589 | } |
590 | ||
591 | /* | |
592 | * Handle all unrecognised system calls. | |
593 | * 0x9f0000 - 0x9fffff are some more esoteric system calls | |
594 | */ | |
595 | #define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE) | |
596 | asmlinkage int arm_syscall(int no, struct pt_regs *regs) | |
597 | { | |
3f2829a3 | 598 | if ((no >> 16) != (__ARM_NR_BASE>> 16)) |
1da177e4 LT |
599 | return bad_syscall(no, regs); |
600 | ||
601 | switch (no & 0xffff) { | |
602 | case 0: /* branch through 0 */ | |
05e792e3 EB |
603 | arm_notify_die("branch through zero", regs, |
604 | SIGSEGV, SEGV_MAPERR, NULL, 0, 0); | |
1da177e4 LT |
605 | return 0; |
606 | ||
607 | case NR(breakpoint): /* SWI BREAK_POINT */ | |
608 | regs->ARM_pc -= thumb_mode(regs) ? 2 : 4; | |
609 | ptrace_break(current, regs); | |
610 | return regs->ARM_r0; | |
611 | ||
612 | /* | |
613 | * Flush a region from virtual address 'r0' to virtual address 'r1' | |
614 | * _exclusive_. There is no alignment requirement on either address; | |
615 | * user space does not need to know the hardware cache layout. | |
616 | * | |
617 | * r2 contains flags. It should ALWAYS be passed as ZERO until it | |
618 | * is defined to be something else. For now we ignore it, but may | |
619 | * the fires of hell burn in your belly if you break this rule. ;) | |
620 | * | |
621 | * (at a later date, we may want to allow this call to not flush | |
622 | * various aspects of the cache. Passing '0' will guarantee that | |
623 | * everything necessary gets flushed to maintain consistency in | |
624 | * the specified region). | |
625 | */ | |
626 | case NR(cacheflush): | |
c5102f59 | 627 | return do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2); |
1da177e4 LT |
628 | |
629 | case NR(usr26): | |
630 | if (!(elf_hwcap & HWCAP_26BIT)) | |
631 | break; | |
632 | regs->ARM_cpsr &= ~MODE32_BIT; | |
633 | return regs->ARM_r0; | |
634 | ||
635 | case NR(usr32): | |
636 | if (!(elf_hwcap & HWCAP_26BIT)) | |
637 | break; | |
638 | regs->ARM_cpsr |= MODE32_BIT; | |
639 | return regs->ARM_r0; | |
640 | ||
641 | case NR(set_tls): | |
fbfb872f | 642 | set_tls(regs->ARM_r0); |
1da177e4 LT |
643 | return 0; |
644 | ||
8fcd6c45 NP |
645 | case NR(get_tls): |
646 | return current_thread_info()->tp_value[0]; | |
647 | ||
1da177e4 LT |
648 | default: |
649 | /* Calls 9f00xx..9f07ff are defined to return -ENOSYS | |
650 | if not implemented, rather than raising SIGILL. This | |
651 | way the calling program can gracefully determine whether | |
652 | a feature is supported. */ | |
bfd2e29f | 653 | if ((no & 0xffff) <= 0x7ff) |
1da177e4 LT |
654 | return -ENOSYS; |
655 | break; | |
656 | } | |
657 | #ifdef CONFIG_DEBUG_USER | |
658 | /* | |
659 | * experience shows that these seem to indicate that | |
660 | * something catastrophic has happened | |
661 | */ | |
662 | if (user_debug & UDBG_SYSCALL) { | |
4ed89f22 | 663 | pr_err("[%d] %s: arm syscall %d\n", |
19c5870c | 664 | task_pid_nr(current), current->comm, no); |
e40c2ec6 | 665 | dump_instr("", regs); |
1da177e4 | 666 | if (user_mode(regs)) { |
652a12ef | 667 | __show_regs(regs); |
49432d4a | 668 | c_backtrace(frame_pointer(regs), processor_mode(regs)); |
1da177e4 LT |
669 | } |
670 | } | |
671 | #endif | |
05e792e3 EB |
672 | arm_notify_die("Oops - bad syscall(2)", regs, SIGILL, ILL_ILLTRP, |
673 | (void __user *)instruction_pointer(regs) - | |
674 | (thumb_mode(regs) ? 2 : 4), | |
675 | no, 0); | |
1da177e4 LT |
676 | return 0; |
677 | } | |
678 | ||
4b0e07a5 | 679 | #ifdef CONFIG_TLS_REG_EMUL |
2d2669b6 NP |
680 | |
681 | /* | |
682 | * We might be running on an ARMv6+ processor which should have the TLS | |
4b0e07a5 NP |
683 | * register but for some reason we can't use it, or maybe an SMP system |
684 | * using a pre-ARMv6 processor (there are apparently a few prototypes like | |
685 | * that in existence) and therefore access to that register must be | |
686 | * emulated. | |
2d2669b6 NP |
687 | */ |
688 | ||
689 | static int get_tp_trap(struct pt_regs *regs, unsigned int instr) | |
690 | { | |
691 | int reg = (instr >> 12) & 15; | |
692 | if (reg == 15) | |
693 | return 1; | |
a4780ade | 694 | regs->uregs[reg] = current_thread_info()->tp_value[0]; |
2d2669b6 NP |
695 | regs->ARM_pc += 4; |
696 | return 0; | |
697 | } | |
698 | ||
699 | static struct undef_hook arm_mrc_hook = { | |
700 | .instr_mask = 0x0fff0fff, | |
701 | .instr_val = 0x0e1d0f70, | |
702 | .cpsr_mask = PSR_T_BIT, | |
703 | .cpsr_val = 0, | |
704 | .fn = get_tp_trap, | |
705 | }; | |
706 | ||
707 | static int __init arm_mrc_hook_init(void) | |
708 | { | |
709 | register_undef_hook(&arm_mrc_hook); | |
710 | return 0; | |
711 | } | |
712 | ||
713 | late_initcall(arm_mrc_hook_init); | |
714 | ||
715 | #endif | |
716 | ||
1da177e4 LT |
717 | /* |
718 | * A data abort trap was taken, but we did not handle the instruction. | |
719 | * Try to abort the user program, or panic if it was the kernel. | |
720 | */ | |
721 | asmlinkage void | |
722 | baddataabort(int code, unsigned long instr, struct pt_regs *regs) | |
723 | { | |
724 | unsigned long addr = instruction_pointer(regs); | |
3eb0f519 | 725 | |
1da177e4 LT |
726 | #ifdef CONFIG_DEBUG_USER |
727 | if (user_debug & UDBG_BADABORT) { | |
4ed89f22 RK |
728 | pr_err("[%d] %s: bad data abort: code %d instr 0x%08lx\n", |
729 | task_pid_nr(current), current->comm, code, instr); | |
e40c2ec6 | 730 | dump_instr(KERN_ERR, regs); |
1da177e4 LT |
731 | show_pte(current->mm, addr); |
732 | } | |
733 | #endif | |
734 | ||
05e792e3 EB |
735 | arm_notify_die("unknown data abort code", regs, |
736 | SIGILL, ILL_ILLOPC, (void __user *)addr, instr, 0); | |
1da177e4 LT |
737 | } |
738 | ||
1da177e4 LT |
739 | void __readwrite_bug(const char *fn) |
740 | { | |
4ed89f22 | 741 | pr_err("%s called, but not implemented\n", fn); |
1da177e4 LT |
742 | BUG(); |
743 | } | |
744 | EXPORT_SYMBOL(__readwrite_bug); | |
745 | ||
69529c0e | 746 | void __pte_error(const char *file, int line, pte_t pte) |
1da177e4 | 747 | { |
4ed89f22 | 748 | pr_err("%s:%d: bad pte %08llx.\n", file, line, (long long)pte_val(pte)); |
1da177e4 LT |
749 | } |
750 | ||
69529c0e | 751 | void __pmd_error(const char *file, int line, pmd_t pmd) |
1da177e4 | 752 | { |
4ed89f22 | 753 | pr_err("%s:%d: bad pmd %08llx.\n", file, line, (long long)pmd_val(pmd)); |
1da177e4 LT |
754 | } |
755 | ||
69529c0e | 756 | void __pgd_error(const char *file, int line, pgd_t pgd) |
1da177e4 | 757 | { |
4ed89f22 | 758 | pr_err("%s:%d: bad pgd %08llx.\n", file, line, (long long)pgd_val(pgd)); |
1da177e4 LT |
759 | } |
760 | ||
761 | asmlinkage void __div0(void) | |
762 | { | |
4ed89f22 | 763 | pr_err("Division by zero in kernel.\n"); |
1da177e4 LT |
764 | dump_stack(); |
765 | } | |
766 | EXPORT_SYMBOL(__div0); | |
767 | ||
768 | void abort(void) | |
769 | { | |
770 | BUG(); | |
771 | ||
772 | /* if that doesn't kill us, halt */ | |
773 | panic("Oops failed to kill thread"); | |
774 | } | |
1da177e4 LT |
775 | |
776 | void __init trap_init(void) | |
5cbad0eb JW |
777 | { |
778 | return; | |
779 | } | |
780 | ||
f6f91b0d RK |
781 | #ifdef CONFIG_KUSER_HELPERS |
782 | static void __init kuser_init(void *vectors) | |
f159f4ed | 783 | { |
f6f91b0d RK |
784 | extern char __kuser_helper_start[], __kuser_helper_end[]; |
785 | int kuser_sz = __kuser_helper_end - __kuser_helper_start; | |
786 | ||
787 | memcpy(vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz); | |
788 | ||
f159f4ed TL |
789 | /* |
790 | * vectors + 0xfe0 = __kuser_get_tls | |
791 | * vectors + 0xfe8 = hardware TLS instruction at 0xffff0fe8 | |
792 | */ | |
793 | if (tls_emu || has_tls_reg) | |
f6f91b0d RK |
794 | memcpy(vectors + 0xfe0, vectors + 0xfe8, 4); |
795 | } | |
796 | #else | |
5761704a | 797 | static inline void __init kuser_init(void *vectors) |
f6f91b0d | 798 | { |
f159f4ed | 799 | } |
f6f91b0d | 800 | #endif |
f159f4ed | 801 | |
94e5a85b | 802 | void __init early_trap_init(void *vectors_base) |
1da177e4 | 803 | { |
55bdd694 | 804 | #ifndef CONFIG_CPU_V7M |
94e5a85b | 805 | unsigned long vectors = (unsigned long)vectors_base; |
7933523d RK |
806 | extern char __stubs_start[], __stubs_end[]; |
807 | extern char __vectors_start[], __vectors_end[]; | |
f928d4f2 | 808 | unsigned i; |
1da177e4 | 809 | |
94e5a85b RK |
810 | vectors_page = vectors_base; |
811 | ||
f928d4f2 RK |
812 | /* |
813 | * Poison the vectors page with an undefined instruction. This | |
814 | * instruction is chosen to be undefined for both ARM and Thumb | |
815 | * ISAs. The Thumb version is an undefined instruction with a | |
816 | * branch back to the undefined instruction. | |
817 | */ | |
818 | for (i = 0; i < PAGE_SIZE / sizeof(u32); i++) | |
819 | ((u32 *)vectors_base)[i] = 0xe7fddef1; | |
820 | ||
7933523d | 821 | /* |
2d2669b6 NP |
822 | * Copy the vectors, stubs and kuser helpers (in entry-armv.S) |
823 | * into the vector page, mapped at 0xffff0000, and ensure these | |
824 | * are visible to the instruction stream. | |
7933523d | 825 | */ |
c760fc19 | 826 | memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start); |
19accfd3 | 827 | memcpy((void *)vectors + 0x1000, __stubs_start, __stubs_end - __stubs_start); |
e00d349e | 828 | |
f6f91b0d | 829 | kuser_init(vectors_base); |
f159f4ed | 830 | |
19accfd3 | 831 | flush_icache_range(vectors, vectors + PAGE_SIZE * 2); |
55bdd694 CM |
832 | #else /* ifndef CONFIG_CPU_V7M */ |
833 | /* | |
834 | * on V7-M there is no need to copy the vector table to a dedicated | |
835 | * memory area. The address is configurable and so a table in the kernel | |
836 | * image can be used. | |
837 | */ | |
838 | #endif | |
1da177e4 | 839 | } |