Commit | Line | Data |
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60ffc30d CM |
1 | /* |
2 | * Based on arch/arm/kernel/traps.c | |
3 | * | |
4 | * Copyright (C) 1995-2009 Russell King | |
5 | * Copyright (C) 2012 ARM Ltd. | |
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 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
18 | */ | |
19 | ||
9fb7410f | 20 | #include <linux/bug.h> |
60ffc30d CM |
21 | #include <linux/signal.h> |
22 | #include <linux/personality.h> | |
23 | #include <linux/kallsyms.h> | |
24 | #include <linux/spinlock.h> | |
25 | #include <linux/uaccess.h> | |
26 | #include <linux/hardirq.h> | |
27 | #include <linux/kdebug.h> | |
28 | #include <linux/module.h> | |
29 | #include <linux/kexec.h> | |
30 | #include <linux/delay.h> | |
31 | #include <linux/init.h> | |
32 | #include <linux/sched.h> | |
33 | #include <linux/syscalls.h> | |
34 | ||
35 | #include <asm/atomic.h> | |
9fb7410f | 36 | #include <asm/bug.h> |
1442b6ed | 37 | #include <asm/debug-monitors.h> |
60a1f02c | 38 | #include <asm/esr.h> |
9fb7410f | 39 | #include <asm/insn.h> |
60ffc30d CM |
40 | #include <asm/traps.h> |
41 | #include <asm/stacktrace.h> | |
42 | #include <asm/exception.h> | |
43 | #include <asm/system_misc.h> | |
44 | ||
45 | static const char *handler[]= { | |
46 | "Synchronous Abort", | |
47 | "IRQ", | |
48 | "FIQ", | |
49 | "Error" | |
50 | }; | |
51 | ||
52 | int show_unhandled_signals = 1; | |
53 | ||
54 | /* | |
55 | * Dump out the contents of some memory nicely... | |
56 | */ | |
57 | static void dump_mem(const char *lvl, const char *str, unsigned long bottom, | |
e147ae6d | 58 | unsigned long top, bool compat) |
60ffc30d CM |
59 | { |
60 | unsigned long first; | |
61 | mm_segment_t fs; | |
62 | int i; | |
e147ae6d | 63 | unsigned int width = compat ? 4 : 8; |
60ffc30d CM |
64 | |
65 | /* | |
66 | * We need to switch to kernel mode so that we can use __get_user | |
67 | * to safely read from kernel space. Note that we now dump the | |
68 | * code first, just in case the backtrace kills us. | |
69 | */ | |
70 | fs = get_fs(); | |
71 | set_fs(KERNEL_DS); | |
72 | ||
73 | printk("%s%s(0x%016lx to 0x%016lx)\n", lvl, str, bottom, top); | |
74 | ||
75 | for (first = bottom & ~31; first < top; first += 32) { | |
76 | unsigned long p; | |
77 | char str[sizeof(" 12345678") * 8 + 1]; | |
78 | ||
79 | memset(str, ' ', sizeof(str)); | |
80 | str[sizeof(str) - 1] = '\0'; | |
81 | ||
e147ae6d RT |
82 | for (p = first, i = 0; i < (32 / width) |
83 | && p < top; i++, p += width) { | |
60ffc30d | 84 | if (p >= bottom && p < top) { |
e147ae6d RT |
85 | unsigned long val; |
86 | ||
87 | if (width == 8) { | |
88 | if (__get_user(val, (unsigned long *)p) == 0) | |
89 | sprintf(str + i * 17, " %016lx", val); | |
90 | else | |
91 | sprintf(str + i * 17, " ????????????????"); | |
92 | } else { | |
93 | if (__get_user(val, (unsigned int *)p) == 0) | |
94 | sprintf(str + i * 9, " %08lx", val); | |
95 | else | |
96 | sprintf(str + i * 9, " ????????"); | |
97 | } | |
60ffc30d CM |
98 | } |
99 | } | |
100 | printk("%s%04lx:%s\n", lvl, first & 0xffff, str); | |
101 | } | |
102 | ||
103 | set_fs(fs); | |
104 | } | |
105 | ||
9f93f3e9 | 106 | static void dump_backtrace_entry(unsigned long where) |
60ffc30d | 107 | { |
9f93f3e9 JL |
108 | /* |
109 | * Note that 'where' can have a physical address, but it's not handled. | |
110 | */ | |
60ffc30d | 111 | print_ip_sym(where); |
60ffc30d CM |
112 | } |
113 | ||
114 | static void dump_instr(const char *lvl, struct pt_regs *regs) | |
115 | { | |
116 | unsigned long addr = instruction_pointer(regs); | |
117 | mm_segment_t fs; | |
118 | char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str; | |
119 | int i; | |
120 | ||
121 | /* | |
122 | * We need to switch to kernel mode so that we can use __get_user | |
123 | * to safely read from kernel space. Note that we now dump the | |
124 | * code first, just in case the backtrace kills us. | |
125 | */ | |
126 | fs = get_fs(); | |
127 | set_fs(KERNEL_DS); | |
128 | ||
129 | for (i = -4; i < 1; i++) { | |
130 | unsigned int val, bad; | |
131 | ||
132 | bad = __get_user(val, &((u32 *)addr)[i]); | |
133 | ||
134 | if (!bad) | |
135 | p += sprintf(p, i == 0 ? "(%08x) " : "%08x ", val); | |
136 | else { | |
137 | p += sprintf(p, "bad PC value"); | |
138 | break; | |
139 | } | |
140 | } | |
141 | printk("%sCode: %s\n", lvl, str); | |
142 | ||
143 | set_fs(fs); | |
144 | } | |
145 | ||
146 | static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) | |
147 | { | |
148 | struct stackframe frame; | |
a80a0eb7 | 149 | unsigned long irq_stack_ptr; |
20380bb3 | 150 | int skip; |
60ffc30d | 151 | |
a80a0eb7 YS |
152 | /* |
153 | * Switching between stacks is valid when tracing current and in | |
154 | * non-preemptible context. | |
155 | */ | |
156 | if (tsk == current && !preemptible()) | |
157 | irq_stack_ptr = IRQ_STACK_PTR(smp_processor_id()); | |
158 | else | |
159 | irq_stack_ptr = 0; | |
160 | ||
60ffc30d CM |
161 | pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk); |
162 | ||
163 | if (!tsk) | |
164 | tsk = current; | |
165 | ||
20380bb3 | 166 | if (tsk == current) { |
60ffc30d | 167 | frame.fp = (unsigned long)__builtin_frame_address(0); |
2128df14 | 168 | frame.sp = current_stack_pointer; |
60ffc30d CM |
169 | frame.pc = (unsigned long)dump_backtrace; |
170 | } else { | |
171 | /* | |
172 | * task blocked in __switch_to | |
173 | */ | |
174 | frame.fp = thread_saved_fp(tsk); | |
175 | frame.sp = thread_saved_sp(tsk); | |
176 | frame.pc = thread_saved_pc(tsk); | |
177 | } | |
20380bb3 AT |
178 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
179 | frame.graph = tsk->curr_ret_stack; | |
180 | #endif | |
60ffc30d | 181 | |
20380bb3 | 182 | skip = !!regs; |
c9cd0ed9 | 183 | printk("Call trace:\n"); |
60ffc30d CM |
184 | while (1) { |
185 | unsigned long where = frame.pc; | |
9f93f3e9 | 186 | unsigned long stack; |
60ffc30d CM |
187 | int ret; |
188 | ||
20380bb3 AT |
189 | /* skip until specified stack frame */ |
190 | if (!skip) { | |
191 | dump_backtrace_entry(where); | |
192 | } else if (frame.fp == regs->regs[29]) { | |
193 | skip = 0; | |
194 | /* | |
195 | * Mostly, this is the case where this function is | |
196 | * called in panic/abort. As exception handler's | |
197 | * stack frame does not contain the corresponding pc | |
198 | * at which an exception has taken place, use regs->pc | |
199 | * instead. | |
200 | */ | |
201 | dump_backtrace_entry(regs->pc); | |
202 | } | |
fe13f95b | 203 | ret = unwind_frame(tsk, &frame); |
60ffc30d CM |
204 | if (ret < 0) |
205 | break; | |
9f93f3e9 | 206 | stack = frame.sp; |
132cd887 AT |
207 | if (in_exception_text(where)) { |
208 | /* | |
209 | * If we switched to the irq_stack before calling this | |
210 | * exception handler, then the pt_regs will be on the | |
211 | * task stack. The easiest way to tell is if the large | |
212 | * pt_regs would overlap with the end of the irq_stack. | |
213 | */ | |
214 | if (stack < irq_stack_ptr && | |
215 | (stack + sizeof(struct pt_regs)) > irq_stack_ptr) | |
216 | stack = IRQ_STACK_TO_TASK_STACK(irq_stack_ptr); | |
217 | ||
9f93f3e9 JL |
218 | dump_mem("", "Exception stack", stack, |
219 | stack + sizeof(struct pt_regs), false); | |
132cd887 | 220 | } |
60ffc30d CM |
221 | } |
222 | } | |
223 | ||
60ffc30d CM |
224 | void show_stack(struct task_struct *tsk, unsigned long *sp) |
225 | { | |
226 | dump_backtrace(NULL, tsk); | |
227 | barrier(); | |
228 | } | |
229 | ||
230 | #ifdef CONFIG_PREEMPT | |
231 | #define S_PREEMPT " PREEMPT" | |
232 | #else | |
233 | #define S_PREEMPT "" | |
234 | #endif | |
60ffc30d | 235 | #define S_SMP " SMP" |
60ffc30d CM |
236 | |
237 | static int __die(const char *str, int err, struct thread_info *thread, | |
238 | struct pt_regs *regs) | |
239 | { | |
240 | struct task_struct *tsk = thread->task; | |
241 | static int die_counter; | |
242 | int ret; | |
243 | ||
244 | pr_emerg("Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n", | |
245 | str, err, ++die_counter); | |
246 | ||
247 | /* trap and error numbers are mostly meaningless on ARM */ | |
248 | ret = notify_die(DIE_OOPS, str, regs, err, 0, SIGSEGV); | |
249 | if (ret == NOTIFY_STOP) | |
250 | return ret; | |
251 | ||
252 | print_modules(); | |
253 | __show_regs(regs); | |
254 | pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n", | |
255 | TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1); | |
256 | ||
257 | if (!user_mode(regs) || in_interrupt()) { | |
258 | dump_mem(KERN_EMERG, "Stack: ", regs->sp, | |
e147ae6d RT |
259 | THREAD_SIZE + (unsigned long)task_stack_page(tsk), |
260 | compat_user_mode(regs)); | |
60ffc30d CM |
261 | dump_backtrace(regs, tsk); |
262 | dump_instr(KERN_EMERG, regs); | |
263 | } | |
264 | ||
265 | return ret; | |
266 | } | |
267 | ||
268 | static DEFINE_RAW_SPINLOCK(die_lock); | |
269 | ||
270 | /* | |
271 | * This function is protected against re-entrancy. | |
272 | */ | |
273 | void die(const char *str, struct pt_regs *regs, int err) | |
274 | { | |
275 | struct thread_info *thread = current_thread_info(); | |
276 | int ret; | |
277 | ||
278 | oops_enter(); | |
279 | ||
280 | raw_spin_lock_irq(&die_lock); | |
281 | console_verbose(); | |
282 | bust_spinlocks(1); | |
283 | ret = __die(str, err, thread, regs); | |
284 | ||
285 | if (regs && kexec_should_crash(thread->task)) | |
286 | crash_kexec(regs); | |
287 | ||
288 | bust_spinlocks(0); | |
373d4d09 | 289 | add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); |
60ffc30d CM |
290 | raw_spin_unlock_irq(&die_lock); |
291 | oops_exit(); | |
292 | ||
293 | if (in_interrupt()) | |
294 | panic("Fatal exception in interrupt"); | |
295 | if (panic_on_oops) | |
296 | panic("Fatal exception"); | |
297 | if (ret != NOTIFY_STOP) | |
298 | do_exit(SIGSEGV); | |
299 | } | |
300 | ||
301 | void arm64_notify_die(const char *str, struct pt_regs *regs, | |
302 | struct siginfo *info, int err) | |
303 | { | |
9141300a CM |
304 | if (user_mode(regs)) { |
305 | current->thread.fault_address = 0; | |
306 | current->thread.fault_code = err; | |
60ffc30d | 307 | force_sig_info(info->si_signo, info, current); |
9141300a | 308 | } else { |
60ffc30d | 309 | die(str, regs, err); |
9141300a | 310 | } |
60ffc30d CM |
311 | } |
312 | ||
9b79f52d PA |
313 | static LIST_HEAD(undef_hook); |
314 | static DEFINE_RAW_SPINLOCK(undef_lock); | |
315 | ||
316 | void register_undef_hook(struct undef_hook *hook) | |
317 | { | |
318 | unsigned long flags; | |
319 | ||
320 | raw_spin_lock_irqsave(&undef_lock, flags); | |
321 | list_add(&hook->node, &undef_hook); | |
322 | raw_spin_unlock_irqrestore(&undef_lock, flags); | |
323 | } | |
324 | ||
325 | void unregister_undef_hook(struct undef_hook *hook) | |
326 | { | |
327 | unsigned long flags; | |
328 | ||
329 | raw_spin_lock_irqsave(&undef_lock, flags); | |
330 | list_del(&hook->node); | |
331 | raw_spin_unlock_irqrestore(&undef_lock, flags); | |
332 | } | |
333 | ||
334 | static int call_undef_hook(struct pt_regs *regs) | |
335 | { | |
336 | struct undef_hook *hook; | |
337 | unsigned long flags; | |
338 | u32 instr; | |
339 | int (*fn)(struct pt_regs *regs, u32 instr) = NULL; | |
340 | void __user *pc = (void __user *)instruction_pointer(regs); | |
341 | ||
342 | if (!user_mode(regs)) | |
343 | return 1; | |
344 | ||
345 | if (compat_thumb_mode(regs)) { | |
346 | /* 16-bit Thumb instruction */ | |
347 | if (get_user(instr, (u16 __user *)pc)) | |
348 | goto exit; | |
349 | instr = le16_to_cpu(instr); | |
350 | if (aarch32_insn_is_wide(instr)) { | |
351 | u32 instr2; | |
352 | ||
353 | if (get_user(instr2, (u16 __user *)(pc + 2))) | |
354 | goto exit; | |
355 | instr2 = le16_to_cpu(instr2); | |
356 | instr = (instr << 16) | instr2; | |
357 | } | |
358 | } else { | |
359 | /* 32-bit ARM instruction */ | |
360 | if (get_user(instr, (u32 __user *)pc)) | |
361 | goto exit; | |
362 | instr = le32_to_cpu(instr); | |
363 | } | |
364 | ||
365 | raw_spin_lock_irqsave(&undef_lock, flags); | |
366 | list_for_each_entry(hook, &undef_hook, node) | |
367 | if ((instr & hook->instr_mask) == hook->instr_val && | |
368 | (regs->pstate & hook->pstate_mask) == hook->pstate_val) | |
369 | fn = hook->fn; | |
370 | ||
371 | raw_spin_unlock_irqrestore(&undef_lock, flags); | |
372 | exit: | |
373 | return fn ? fn(regs, instr) : 1; | |
374 | } | |
375 | ||
60ffc30d CM |
376 | asmlinkage void __exception do_undefinstr(struct pt_regs *regs) |
377 | { | |
378 | siginfo_t info; | |
379 | void __user *pc = (void __user *)instruction_pointer(regs); | |
380 | ||
60ffc30d | 381 | /* check for AArch32 breakpoint instructions */ |
1442b6ed | 382 | if (!aarch32_break_handler(regs)) |
60ffc30d | 383 | return; |
60ffc30d | 384 | |
9b79f52d PA |
385 | if (call_undef_hook(regs) == 0) |
386 | return; | |
387 | ||
f871d268 | 388 | if (unhandled_signal(current, SIGILL) && show_unhandled_signals_ratelimited()) { |
60ffc30d CM |
389 | pr_info("%s[%d]: undefined instruction: pc=%p\n", |
390 | current->comm, task_pid_nr(current), pc); | |
391 | dump_instr(KERN_INFO, regs); | |
392 | } | |
393 | ||
394 | info.si_signo = SIGILL; | |
395 | info.si_errno = 0; | |
396 | info.si_code = ILL_ILLOPC; | |
397 | info.si_addr = pc; | |
398 | ||
399 | arm64_notify_die("Oops - undefined instruction", regs, &info, 0); | |
400 | } | |
401 | ||
402 | long compat_arm_syscall(struct pt_regs *regs); | |
403 | ||
404 | asmlinkage long do_ni_syscall(struct pt_regs *regs) | |
405 | { | |
406 | #ifdef CONFIG_COMPAT | |
407 | long ret; | |
408 | if (is_compat_task()) { | |
409 | ret = compat_arm_syscall(regs); | |
410 | if (ret != -ENOSYS) | |
411 | return ret; | |
412 | } | |
413 | #endif | |
414 | ||
86dca36e | 415 | if (show_unhandled_signals_ratelimited()) { |
60ffc30d CM |
416 | pr_info("%s[%d]: syscall %d\n", current->comm, |
417 | task_pid_nr(current), (int)regs->syscallno); | |
418 | dump_instr("", regs); | |
419 | if (user_mode(regs)) | |
420 | __show_regs(regs); | |
421 | } | |
422 | ||
423 | return sys_ni_syscall(); | |
424 | } | |
425 | ||
60a1f02c MR |
426 | static const char *esr_class_str[] = { |
427 | [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC", | |
428 | [ESR_ELx_EC_UNKNOWN] = "Unknown/Uncategorized", | |
429 | [ESR_ELx_EC_WFx] = "WFI/WFE", | |
430 | [ESR_ELx_EC_CP15_32] = "CP15 MCR/MRC", | |
431 | [ESR_ELx_EC_CP15_64] = "CP15 MCRR/MRRC", | |
432 | [ESR_ELx_EC_CP14_MR] = "CP14 MCR/MRC", | |
433 | [ESR_ELx_EC_CP14_LS] = "CP14 LDC/STC", | |
434 | [ESR_ELx_EC_FP_ASIMD] = "ASIMD", | |
435 | [ESR_ELx_EC_CP10_ID] = "CP10 MRC/VMRS", | |
436 | [ESR_ELx_EC_CP14_64] = "CP14 MCRR/MRRC", | |
437 | [ESR_ELx_EC_ILL] = "PSTATE.IL", | |
438 | [ESR_ELx_EC_SVC32] = "SVC (AArch32)", | |
439 | [ESR_ELx_EC_HVC32] = "HVC (AArch32)", | |
440 | [ESR_ELx_EC_SMC32] = "SMC (AArch32)", | |
441 | [ESR_ELx_EC_SVC64] = "SVC (AArch64)", | |
442 | [ESR_ELx_EC_HVC64] = "HVC (AArch64)", | |
443 | [ESR_ELx_EC_SMC64] = "SMC (AArch64)", | |
444 | [ESR_ELx_EC_SYS64] = "MSR/MRS (AArch64)", | |
445 | [ESR_ELx_EC_IMP_DEF] = "EL3 IMP DEF", | |
446 | [ESR_ELx_EC_IABT_LOW] = "IABT (lower EL)", | |
447 | [ESR_ELx_EC_IABT_CUR] = "IABT (current EL)", | |
448 | [ESR_ELx_EC_PC_ALIGN] = "PC Alignment", | |
449 | [ESR_ELx_EC_DABT_LOW] = "DABT (lower EL)", | |
450 | [ESR_ELx_EC_DABT_CUR] = "DABT (current EL)", | |
451 | [ESR_ELx_EC_SP_ALIGN] = "SP Alignment", | |
452 | [ESR_ELx_EC_FP_EXC32] = "FP (AArch32)", | |
453 | [ESR_ELx_EC_FP_EXC64] = "FP (AArch64)", | |
454 | [ESR_ELx_EC_SERROR] = "SError", | |
455 | [ESR_ELx_EC_BREAKPT_LOW] = "Breakpoint (lower EL)", | |
456 | [ESR_ELx_EC_BREAKPT_CUR] = "Breakpoint (current EL)", | |
457 | [ESR_ELx_EC_SOFTSTP_LOW] = "Software Step (lower EL)", | |
458 | [ESR_ELx_EC_SOFTSTP_CUR] = "Software Step (current EL)", | |
459 | [ESR_ELx_EC_WATCHPT_LOW] = "Watchpoint (lower EL)", | |
460 | [ESR_ELx_EC_WATCHPT_CUR] = "Watchpoint (current EL)", | |
461 | [ESR_ELx_EC_BKPT32] = "BKPT (AArch32)", | |
462 | [ESR_ELx_EC_VECTOR32] = "Vector catch (AArch32)", | |
463 | [ESR_ELx_EC_BRK64] = "BRK (AArch64)", | |
464 | }; | |
465 | ||
466 | const char *esr_get_class_string(u32 esr) | |
467 | { | |
468 | return esr_class_str[esr >> ESR_ELx_EC_SHIFT]; | |
469 | } | |
470 | ||
60ffc30d CM |
471 | /* |
472 | * bad_mode handles the impossible case in the exception vector. | |
473 | */ | |
474 | asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr) | |
475 | { | |
9955ac47 MR |
476 | siginfo_t info; |
477 | void __user *pc = (void __user *)instruction_pointer(regs); | |
60ffc30d CM |
478 | console_verbose(); |
479 | ||
8051f4d1 MR |
480 | pr_crit("Bad mode in %s handler detected on CPU%d, code 0x%08x -- %s\n", |
481 | handler[reason], smp_processor_id(), esr, | |
482 | esr_get_class_string(esr)); | |
9955ac47 MR |
483 | __show_regs(regs); |
484 | ||
485 | info.si_signo = SIGILL; | |
486 | info.si_errno = 0; | |
487 | info.si_code = ILL_ILLOPC; | |
488 | info.si_addr = pc; | |
60ffc30d | 489 | |
9955ac47 | 490 | arm64_notify_die("Oops - bad mode", regs, &info, 0); |
60ffc30d CM |
491 | } |
492 | ||
493 | void __pte_error(const char *file, int line, unsigned long val) | |
494 | { | |
c9cd0ed9 | 495 | pr_err("%s:%d: bad pte %016lx.\n", file, line, val); |
60ffc30d CM |
496 | } |
497 | ||
498 | void __pmd_error(const char *file, int line, unsigned long val) | |
499 | { | |
c9cd0ed9 | 500 | pr_err("%s:%d: bad pmd %016lx.\n", file, line, val); |
60ffc30d CM |
501 | } |
502 | ||
c79b954b JL |
503 | void __pud_error(const char *file, int line, unsigned long val) |
504 | { | |
c9cd0ed9 | 505 | pr_err("%s:%d: bad pud %016lx.\n", file, line, val); |
c79b954b JL |
506 | } |
507 | ||
60ffc30d CM |
508 | void __pgd_error(const char *file, int line, unsigned long val) |
509 | { | |
c9cd0ed9 | 510 | pr_err("%s:%d: bad pgd %016lx.\n", file, line, val); |
60ffc30d CM |
511 | } |
512 | ||
9fb7410f DM |
513 | /* GENERIC_BUG traps */ |
514 | ||
515 | int is_valid_bugaddr(unsigned long addr) | |
516 | { | |
517 | /* | |
518 | * bug_handler() only called for BRK #BUG_BRK_IMM. | |
519 | * So the answer is trivial -- any spurious instances with no | |
520 | * bug table entry will be rejected by report_bug() and passed | |
521 | * back to the debug-monitors code and handled as a fatal | |
522 | * unexpected debug exception. | |
523 | */ | |
524 | return 1; | |
525 | } | |
526 | ||
527 | static int bug_handler(struct pt_regs *regs, unsigned int esr) | |
528 | { | |
529 | if (user_mode(regs)) | |
530 | return DBG_HOOK_ERROR; | |
531 | ||
532 | switch (report_bug(regs->pc, regs)) { | |
533 | case BUG_TRAP_TYPE_BUG: | |
534 | die("Oops - BUG", regs, 0); | |
535 | break; | |
536 | ||
537 | case BUG_TRAP_TYPE_WARN: | |
a4653228 DM |
538 | /* Ideally, report_bug() should backtrace for us... but no. */ |
539 | dump_backtrace(regs, NULL); | |
9fb7410f DM |
540 | break; |
541 | ||
542 | default: | |
543 | /* unknown/unrecognised bug trap type */ | |
544 | return DBG_HOOK_ERROR; | |
545 | } | |
546 | ||
547 | /* If thread survives, skip over the BUG instruction and continue: */ | |
548 | regs->pc += AARCH64_INSN_SIZE; /* skip BRK and resume */ | |
549 | return DBG_HOOK_HANDLED; | |
550 | } | |
551 | ||
552 | static struct break_hook bug_break_hook = { | |
553 | .esr_val = 0xf2000000 | BUG_BRK_IMM, | |
554 | .esr_mask = 0xffffffff, | |
555 | .fn = bug_handler, | |
556 | }; | |
557 | ||
558 | /* | |
559 | * Initial handler for AArch64 BRK exceptions | |
560 | * This handler only used until debug_traps_init(). | |
561 | */ | |
562 | int __init early_brk64(unsigned long addr, unsigned int esr, | |
563 | struct pt_regs *regs) | |
564 | { | |
565 | return bug_handler(regs, esr) != DBG_HOOK_HANDLED; | |
566 | } | |
567 | ||
568 | /* This registration must happen early, before debug_traps_init(). */ | |
60ffc30d CM |
569 | void __init trap_init(void) |
570 | { | |
9fb7410f | 571 | register_break_hook(&bug_break_hook); |
60ffc30d | 572 | } |