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9#include <linux/bug.h>
10#include <linux/context_tracking.h>
11#include <linux/signal.h>
12#include <linux/personality.h>
13#include <linux/kallsyms.h>
14#include <linux/kprobes.h>
15#include <linux/spinlock.h>
16#include <linux/uaccess.h>
17#include <linux/hardirq.h>
18#include <linux/kdebug.h>
19#include <linux/module.h>
20#include <linux/kexec.h>
21#include <linux/delay.h>
22#include <linux/init.h>
23#include <linux/sched/signal.h>
24#include <linux/sched/debug.h>
25#include <linux/sched/task_stack.h>
26#include <linux/sizes.h>
27#include <linux/syscalls.h>
28#include <linux/mm_types.h>
29#include <linux/kasan.h>
30
31#include <asm/atomic.h>
32#include <asm/bug.h>
33#include <asm/cpufeature.h>
34#include <asm/daifflags.h>
35#include <asm/debug-monitors.h>
36#include <asm/esr.h>
37#include <asm/exception.h>
38#include <asm/extable.h>
39#include <asm/insn.h>
40#include <asm/kprobes.h>
41#include <asm/patching.h>
42#include <asm/traps.h>
43#include <asm/smp.h>
44#include <asm/stack_pointer.h>
45#include <asm/stacktrace.h>
46#include <asm/system_misc.h>
47#include <asm/sysreg.h>
48
49static bool __kprobes __check_eq(unsigned long pstate)
50{
51 return (pstate & PSR_Z_BIT) != 0;
52}
53
54static bool __kprobes __check_ne(unsigned long pstate)
55{
56 return (pstate & PSR_Z_BIT) == 0;
57}
58
59static bool __kprobes __check_cs(unsigned long pstate)
60{
61 return (pstate & PSR_C_BIT) != 0;
62}
63
64static bool __kprobes __check_cc(unsigned long pstate)
65{
66 return (pstate & PSR_C_BIT) == 0;
67}
68
69static bool __kprobes __check_mi(unsigned long pstate)
70{
71 return (pstate & PSR_N_BIT) != 0;
72}
73
74static bool __kprobes __check_pl(unsigned long pstate)
75{
76 return (pstate & PSR_N_BIT) == 0;
77}
78
79static bool __kprobes __check_vs(unsigned long pstate)
80{
81 return (pstate & PSR_V_BIT) != 0;
82}
83
84static bool __kprobes __check_vc(unsigned long pstate)
85{
86 return (pstate & PSR_V_BIT) == 0;
87}
88
89static bool __kprobes __check_hi(unsigned long pstate)
90{
91 pstate &= ~(pstate >> 1);
92 return (pstate & PSR_C_BIT) != 0;
93}
94
95static bool __kprobes __check_ls(unsigned long pstate)
96{
97 pstate &= ~(pstate >> 1);
98 return (pstate & PSR_C_BIT) == 0;
99}
100
101static bool __kprobes __check_ge(unsigned long pstate)
102{
103 pstate ^= (pstate << 3);
104 return (pstate & PSR_N_BIT) == 0;
105}
106
107static bool __kprobes __check_lt(unsigned long pstate)
108{
109 pstate ^= (pstate << 3);
110 return (pstate & PSR_N_BIT) != 0;
111}
112
113static bool __kprobes __check_gt(unsigned long pstate)
114{
115
116 unsigned long temp = pstate ^ (pstate << 3);
117
118 temp |= (pstate << 1);
119 return (temp & PSR_N_BIT) == 0;
120}
121
122static bool __kprobes __check_le(unsigned long pstate)
123{
124
125 unsigned long temp = pstate ^ (pstate << 3);
126
127 temp |= (pstate << 1);
128 return (temp & PSR_N_BIT) != 0;
129}
130
131static bool __kprobes __check_al(unsigned long pstate)
132{
133 return true;
134}
135
136
137
138
139
140pstate_check_t * const aarch32_opcode_cond_checks[16] = {
141 __check_eq, __check_ne, __check_cs, __check_cc,
142 __check_mi, __check_pl, __check_vs, __check_vc,
143 __check_hi, __check_ls, __check_ge, __check_lt,
144 __check_gt, __check_le, __check_al, __check_al
145};
146
147int show_unhandled_signals = 0;
148
149static void dump_kernel_instr(const char *lvl, struct pt_regs *regs)
150{
151 unsigned long addr = instruction_pointer(regs);
152 char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
153 int i;
154
155 if (user_mode(regs))
156 return;
157
158 for (i = -4; i < 1; i++) {
159 unsigned int val, bad;
160
161 bad = aarch64_insn_read(&((u32 *)addr)[i], &val);
162
163 if (!bad)
164 p += sprintf(p, i == 0 ? "(%08x) " : "%08x ", val);
165 else {
166 p += sprintf(p, "bad PC value");
167 break;
168 }
169 }
170
171 printk("%sCode: %s\n", lvl, str);
172}
173
174#ifdef CONFIG_PREEMPT
175#define S_PREEMPT " PREEMPT"
176#elif defined(CONFIG_PREEMPT_RT)
177#define S_PREEMPT " PREEMPT_RT"
178#else
179#define S_PREEMPT ""
180#endif
181
182#define S_SMP " SMP"
183
184static int __die(const char *str, int err, struct pt_regs *regs)
185{
186 static int die_counter;
187 int ret;
188
189 pr_emerg("Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n",
190 str, err, ++die_counter);
191
192
193 ret = notify_die(DIE_OOPS, str, regs, err, 0, SIGSEGV);
194 if (ret == NOTIFY_STOP)
195 return ret;
196
197 print_modules();
198 show_regs(regs);
199
200 dump_kernel_instr(KERN_EMERG, regs);
201
202 return ret;
203}
204
205static DEFINE_RAW_SPINLOCK(die_lock);
206
207
208
209
210void die(const char *str, struct pt_regs *regs, int err)
211{
212 int ret;
213 unsigned long flags;
214
215 raw_spin_lock_irqsave(&die_lock, flags);
216
217 oops_enter();
218
219 console_verbose();
220 bust_spinlocks(1);
221 ret = __die(str, err, regs);
222
223 if (regs && kexec_should_crash(current))
224 crash_kexec(regs);
225
226 bust_spinlocks(0);
227 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
228 oops_exit();
229
230 if (in_interrupt())
231 panic("%s: Fatal exception in interrupt", str);
232 if (panic_on_oops)
233 panic("%s: Fatal exception", str);
234
235 raw_spin_unlock_irqrestore(&die_lock, flags);
236
237 if (ret != NOTIFY_STOP)
238 do_exit(SIGSEGV);
239}
240
241static void arm64_show_signal(int signo, const char *str)
242{
243 static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL,
244 DEFAULT_RATELIMIT_BURST);
245 struct task_struct *tsk = current;
246 unsigned int esr = tsk->thread.fault_code;
247 struct pt_regs *regs = task_pt_regs(tsk);
248
249
250 if (!show_unhandled_signals ||
251 !unhandled_signal(tsk, signo) ||
252 !__ratelimit(&rs))
253 return;
254
255 pr_info("%s[%d]: unhandled exception: ", tsk->comm, task_pid_nr(tsk));
256 if (esr)
257 pr_cont("%s, ESR 0x%08x, ", esr_get_class_string(esr), esr);
258
259 pr_cont("%s", str);
260 print_vma_addr(KERN_CONT " in ", regs->pc);
261 pr_cont("\n");
262 __show_regs(regs);
263}
264
265void arm64_force_sig_fault(int signo, int code, unsigned long far,
266 const char *str)
267{
268 arm64_show_signal(signo, str);
269 if (signo == SIGKILL)
270 force_sig(SIGKILL);
271 else
272 force_sig_fault(signo, code, (void __user *)far);
273}
274
275void arm64_force_sig_mceerr(int code, unsigned long far, short lsb,
276 const char *str)
277{
278 arm64_show_signal(SIGBUS, str);
279 force_sig_mceerr(code, (void __user *)far, lsb);
280}
281
282void arm64_force_sig_ptrace_errno_trap(int errno, unsigned long far,
283 const char *str)
284{
285 arm64_show_signal(SIGTRAP, str);
286 force_sig_ptrace_errno_trap(errno, (void __user *)far);
287}
288
289void arm64_notify_die(const char *str, struct pt_regs *regs,
290 int signo, int sicode, unsigned long far,
291 int err)
292{
293 if (user_mode(regs)) {
294 WARN_ON(regs != current_pt_regs());
295 current->thread.fault_address = 0;
296 current->thread.fault_code = err;
297
298 arm64_force_sig_fault(signo, sicode, far, str);
299 } else {
300 die(str, regs, err);
301 }
302}
303
304#ifdef CONFIG_COMPAT
305#define PSTATE_IT_1_0_SHIFT 25
306#define PSTATE_IT_1_0_MASK (0x3 << PSTATE_IT_1_0_SHIFT)
307#define PSTATE_IT_7_2_SHIFT 10
308#define PSTATE_IT_7_2_MASK (0x3f << PSTATE_IT_7_2_SHIFT)
309
310static u32 compat_get_it_state(struct pt_regs *regs)
311{
312 u32 it, pstate = regs->pstate;
313
314 it = (pstate & PSTATE_IT_1_0_MASK) >> PSTATE_IT_1_0_SHIFT;
315 it |= ((pstate & PSTATE_IT_7_2_MASK) >> PSTATE_IT_7_2_SHIFT) << 2;
316
317 return it;
318}
319
320static void compat_set_it_state(struct pt_regs *regs, u32 it)
321{
322 u32 pstate_it;
323
324 pstate_it = (it << PSTATE_IT_1_0_SHIFT) & PSTATE_IT_1_0_MASK;
325 pstate_it |= ((it >> 2) << PSTATE_IT_7_2_SHIFT) & PSTATE_IT_7_2_MASK;
326
327 regs->pstate &= ~PSR_AA32_IT_MASK;
328 regs->pstate |= pstate_it;
329}
330
331static void advance_itstate(struct pt_regs *regs)
332{
333 u32 it;
334
335
336 if (!(regs->pstate & PSR_AA32_T_BIT) ||
337 !(regs->pstate & PSR_AA32_IT_MASK))
338 return;
339
340 it = compat_get_it_state(regs);
341
342
343
344
345
346 if (!(it & 7))
347 it = 0;
348 else
349 it = (it & 0xe0) | ((it << 1) & 0x1f);
350
351 compat_set_it_state(regs, it);
352}
353#else
354static void advance_itstate(struct pt_regs *regs)
355{
356}
357#endif
358
359void arm64_skip_faulting_instruction(struct pt_regs *regs, unsigned long size)
360{
361 regs->pc += size;
362
363
364
365
366
367 if (user_mode(regs))
368 user_fastforward_single_step(current);
369
370 if (compat_user_mode(regs))
371 advance_itstate(regs);
372 else
373 regs->pstate &= ~PSR_BTYPE_MASK;
374}
375
376static LIST_HEAD(undef_hook);
377static DEFINE_RAW_SPINLOCK(undef_lock);
378
379void register_undef_hook(struct undef_hook *hook)
380{
381 unsigned long flags;
382
383 raw_spin_lock_irqsave(&undef_lock, flags);
384 list_add(&hook->node, &undef_hook);
385 raw_spin_unlock_irqrestore(&undef_lock, flags);
386}
387
388void unregister_undef_hook(struct undef_hook *hook)
389{
390 unsigned long flags;
391
392 raw_spin_lock_irqsave(&undef_lock, flags);
393 list_del(&hook->node);
394 raw_spin_unlock_irqrestore(&undef_lock, flags);
395}
396
397static int call_undef_hook(struct pt_regs *regs)
398{
399 struct undef_hook *hook;
400 unsigned long flags;
401 u32 instr;
402 int (*fn)(struct pt_regs *regs, u32 instr) = NULL;
403 void __user *pc = (void __user *)instruction_pointer(regs);
404
405 if (!user_mode(regs)) {
406 __le32 instr_le;
407 if (get_kernel_nofault(instr_le, (__force __le32 *)pc))
408 goto exit;
409 instr = le32_to_cpu(instr_le);
410 } else if (compat_thumb_mode(regs)) {
411
412 __le16 instr_le;
413 if (get_user(instr_le, (__le16 __user *)pc))
414 goto exit;
415 instr = le16_to_cpu(instr_le);
416 if (aarch32_insn_is_wide(instr)) {
417 u32 instr2;
418
419 if (get_user(instr_le, (__le16 __user *)(pc + 2)))
420 goto exit;
421 instr2 = le16_to_cpu(instr_le);
422 instr = (instr << 16) | instr2;
423 }
424 } else {
425
426 __le32 instr_le;
427 if (get_user(instr_le, (__le32 __user *)pc))
428 goto exit;
429 instr = le32_to_cpu(instr_le);
430 }
431
432 raw_spin_lock_irqsave(&undef_lock, flags);
433 list_for_each_entry(hook, &undef_hook, node)
434 if ((instr & hook->instr_mask) == hook->instr_val &&
435 (regs->pstate & hook->pstate_mask) == hook->pstate_val)
436 fn = hook->fn;
437
438 raw_spin_unlock_irqrestore(&undef_lock, flags);
439exit:
440 return fn ? fn(regs, instr) : 1;
441}
442
443void force_signal_inject(int signal, int code, unsigned long address, unsigned int err)
444{
445 const char *desc;
446 struct pt_regs *regs = current_pt_regs();
447
448 if (WARN_ON(!user_mode(regs)))
449 return;
450
451 switch (signal) {
452 case SIGILL:
453 desc = "undefined instruction";
454 break;
455 case SIGSEGV:
456 desc = "illegal memory access";
457 break;
458 default:
459 desc = "unknown or unrecoverable error";
460 break;
461 }
462
463
464 if (WARN_ON(signal != SIGKILL &&
465 siginfo_layout(signal, code) != SIL_FAULT)) {
466 signal = SIGKILL;
467 }
468
469 arm64_notify_die(desc, regs, signal, code, address, err);
470}
471
472
473
474
475void arm64_notify_segfault(unsigned long addr)
476{
477 int code;
478
479 mmap_read_lock(current->mm);
480 if (find_vma(current->mm, untagged_addr(addr)) == NULL)
481 code = SEGV_MAPERR;
482 else
483 code = SEGV_ACCERR;
484 mmap_read_unlock(current->mm);
485
486 force_signal_inject(SIGSEGV, code, addr, 0);
487}
488
489void do_undefinstr(struct pt_regs *regs)
490{
491
492 if (!aarch32_break_handler(regs))
493 return;
494
495 if (call_undef_hook(regs) == 0)
496 return;
497
498 BUG_ON(!user_mode(regs));
499 force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc, 0);
500}
501NOKPROBE_SYMBOL(do_undefinstr);
502
503void do_bti(struct pt_regs *regs)
504{
505 BUG_ON(!user_mode(regs));
506 force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc, 0);
507}
508NOKPROBE_SYMBOL(do_bti);
509
510void do_ptrauth_fault(struct pt_regs *regs, unsigned int esr)
511{
512
513
514
515
516 BUG_ON(!user_mode(regs));
517 force_signal_inject(SIGILL, ILL_ILLOPN, regs->pc, esr);
518}
519NOKPROBE_SYMBOL(do_ptrauth_fault);
520
521#define __user_cache_maint(insn, address, res) \
522 if (address >= user_addr_max()) { \
523 res = -EFAULT; \
524 } else { \
525 uaccess_ttbr0_enable(); \
526 asm volatile ( \
527 "1: " insn ", %1\n" \
528 " mov %w0, #0\n" \
529 "2:\n" \
530 " .pushsection .fixup,\"ax\"\n" \
531 " .align 2\n" \
532 "3: mov %w0, %w2\n" \
533 " b 2b\n" \
534 " .popsection\n" \
535 _ASM_EXTABLE(1b, 3b) \
536 : "=r" (res) \
537 : "r" (address), "i" (-EFAULT)); \
538 uaccess_ttbr0_disable(); \
539 }
540
541static void user_cache_maint_handler(unsigned int esr, struct pt_regs *regs)
542{
543 unsigned long tagged_address, address;
544 int rt = ESR_ELx_SYS64_ISS_RT(esr);
545 int crm = (esr & ESR_ELx_SYS64_ISS_CRM_MASK) >> ESR_ELx_SYS64_ISS_CRM_SHIFT;
546 int ret = 0;
547
548 tagged_address = pt_regs_read_reg(regs, rt);
549 address = untagged_addr(tagged_address);
550
551 switch (crm) {
552 case ESR_ELx_SYS64_ISS_CRM_DC_CVAU:
553 __user_cache_maint("dc civac", address, ret);
554 break;
555 case ESR_ELx_SYS64_ISS_CRM_DC_CVAC:
556 __user_cache_maint("dc civac", address, ret);
557 break;
558 case ESR_ELx_SYS64_ISS_CRM_DC_CVADP:
559 __user_cache_maint("sys 3, c7, c13, 1", address, ret);
560 break;
561 case ESR_ELx_SYS64_ISS_CRM_DC_CVAP:
562 __user_cache_maint("sys 3, c7, c12, 1", address, ret);
563 break;
564 case ESR_ELx_SYS64_ISS_CRM_DC_CIVAC:
565 __user_cache_maint("dc civac", address, ret);
566 break;
567 case ESR_ELx_SYS64_ISS_CRM_IC_IVAU:
568 __user_cache_maint("ic ivau", address, ret);
569 break;
570 default:
571 force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc, 0);
572 return;
573 }
574
575 if (ret)
576 arm64_notify_segfault(tagged_address);
577 else
578 arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
579}
580
581static void ctr_read_handler(unsigned int esr, struct pt_regs *regs)
582{
583 int rt = ESR_ELx_SYS64_ISS_RT(esr);
584 unsigned long val = arm64_ftr_reg_user_value(&arm64_ftr_reg_ctrel0);
585
586 if (cpus_have_const_cap(ARM64_WORKAROUND_1542419)) {
587
588 val &= ~BIT(CTR_DIC_SHIFT);
589
590
591 val &= ~CTR_IMINLINE_MASK;
592 val |= (PAGE_SHIFT - 2) & CTR_IMINLINE_MASK;
593 }
594
595 pt_regs_write_reg(regs, rt, val);
596
597 arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
598}
599
600static void cntvct_read_handler(unsigned int esr, struct pt_regs *regs)
601{
602 int rt = ESR_ELx_SYS64_ISS_RT(esr);
603
604 pt_regs_write_reg(regs, rt, arch_timer_read_counter());
605 arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
606}
607
608static void cntfrq_read_handler(unsigned int esr, struct pt_regs *regs)
609{
610 int rt = ESR_ELx_SYS64_ISS_RT(esr);
611
612 pt_regs_write_reg(regs, rt, arch_timer_get_rate());
613 arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
614}
615
616static void mrs_handler(unsigned int esr, struct pt_regs *regs)
617{
618 u32 sysreg, rt;
619
620 rt = ESR_ELx_SYS64_ISS_RT(esr);
621 sysreg = esr_sys64_to_sysreg(esr);
622
623 if (do_emulate_mrs(regs, sysreg, rt) != 0)
624 force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc, 0);
625}
626
627static void wfi_handler(unsigned int esr, struct pt_regs *regs)
628{
629 arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
630}
631
632struct sys64_hook {
633 unsigned int esr_mask;
634 unsigned int esr_val;
635 void (*handler)(unsigned int esr, struct pt_regs *regs);
636};
637
638static const struct sys64_hook sys64_hooks[] = {
639 {
640 .esr_mask = ESR_ELx_SYS64_ISS_EL0_CACHE_OP_MASK,
641 .esr_val = ESR_ELx_SYS64_ISS_EL0_CACHE_OP_VAL,
642 .handler = user_cache_maint_handler,
643 },
644 {
645
646 .esr_mask = ESR_ELx_SYS64_ISS_SYS_OP_MASK,
647 .esr_val = ESR_ELx_SYS64_ISS_SYS_CTR_READ,
648 .handler = ctr_read_handler,
649 },
650 {
651
652 .esr_mask = ESR_ELx_SYS64_ISS_SYS_OP_MASK,
653 .esr_val = ESR_ELx_SYS64_ISS_SYS_CNTVCT,
654 .handler = cntvct_read_handler,
655 },
656 {
657
658 .esr_mask = ESR_ELx_SYS64_ISS_SYS_OP_MASK,
659 .esr_val = ESR_ELx_SYS64_ISS_SYS_CNTFRQ,
660 .handler = cntfrq_read_handler,
661 },
662 {
663
664 .esr_mask = ESR_ELx_SYS64_ISS_SYS_MRS_OP_MASK,
665 .esr_val = ESR_ELx_SYS64_ISS_SYS_MRS_OP_VAL,
666 .handler = mrs_handler,
667 },
668 {
669
670 .esr_mask = ESR_ELx_WFx_MASK,
671 .esr_val = ESR_ELx_WFx_WFI_VAL,
672 .handler = wfi_handler,
673 },
674 {},
675};
676
677#ifdef CONFIG_COMPAT
678static bool cp15_cond_valid(unsigned int esr, struct pt_regs *regs)
679{
680 int cond;
681
682
683 if (!(esr & ESR_ELx_CV)) {
684 u32 it;
685
686 it = compat_get_it_state(regs);
687 if (!it)
688 return true;
689
690 cond = it >> 4;
691 } else {
692 cond = (esr & ESR_ELx_COND_MASK) >> ESR_ELx_COND_SHIFT;
693 }
694
695 return aarch32_opcode_cond_checks[cond](regs->pstate);
696}
697
698static void compat_cntfrq_read_handler(unsigned int esr, struct pt_regs *regs)
699{
700 int reg = (esr & ESR_ELx_CP15_32_ISS_RT_MASK) >> ESR_ELx_CP15_32_ISS_RT_SHIFT;
701
702 pt_regs_write_reg(regs, reg, arch_timer_get_rate());
703 arm64_skip_faulting_instruction(regs, 4);
704}
705
706static const struct sys64_hook cp15_32_hooks[] = {
707 {
708 .esr_mask = ESR_ELx_CP15_32_ISS_SYS_MASK,
709 .esr_val = ESR_ELx_CP15_32_ISS_SYS_CNTFRQ,
710 .handler = compat_cntfrq_read_handler,
711 },
712 {},
713};
714
715static void compat_cntvct_read_handler(unsigned int esr, struct pt_regs *regs)
716{
717 int rt = (esr & ESR_ELx_CP15_64_ISS_RT_MASK) >> ESR_ELx_CP15_64_ISS_RT_SHIFT;
718 int rt2 = (esr & ESR_ELx_CP15_64_ISS_RT2_MASK) >> ESR_ELx_CP15_64_ISS_RT2_SHIFT;
719 u64 val = arch_timer_read_counter();
720
721 pt_regs_write_reg(regs, rt, lower_32_bits(val));
722 pt_regs_write_reg(regs, rt2, upper_32_bits(val));
723 arm64_skip_faulting_instruction(regs, 4);
724}
725
726static const struct sys64_hook cp15_64_hooks[] = {
727 {
728 .esr_mask = ESR_ELx_CP15_64_ISS_SYS_MASK,
729 .esr_val = ESR_ELx_CP15_64_ISS_SYS_CNTVCT,
730 .handler = compat_cntvct_read_handler,
731 },
732 {},
733};
734
735void do_cp15instr(unsigned int esr, struct pt_regs *regs)
736{
737 const struct sys64_hook *hook, *hook_base;
738
739 if (!cp15_cond_valid(esr, regs)) {
740
741
742
743
744 arm64_skip_faulting_instruction(regs, 4);
745 return;
746 }
747
748 switch (ESR_ELx_EC(esr)) {
749 case ESR_ELx_EC_CP15_32:
750 hook_base = cp15_32_hooks;
751 break;
752 case ESR_ELx_EC_CP15_64:
753 hook_base = cp15_64_hooks;
754 break;
755 default:
756 do_undefinstr(regs);
757 return;
758 }
759
760 for (hook = hook_base; hook->handler; hook++)
761 if ((hook->esr_mask & esr) == hook->esr_val) {
762 hook->handler(esr, regs);
763 return;
764 }
765
766
767
768
769
770
771 do_undefinstr(regs);
772}
773NOKPROBE_SYMBOL(do_cp15instr);
774#endif
775
776void do_sysinstr(unsigned int esr, struct pt_regs *regs)
777{
778 const struct sys64_hook *hook;
779
780 for (hook = sys64_hooks; hook->handler; hook++)
781 if ((hook->esr_mask & esr) == hook->esr_val) {
782 hook->handler(esr, regs);
783 return;
784 }
785
786
787
788
789
790
791 do_undefinstr(regs);
792}
793NOKPROBE_SYMBOL(do_sysinstr);
794
795static const char *esr_class_str[] = {
796 [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC",
797 [ESR_ELx_EC_UNKNOWN] = "Unknown/Uncategorized",
798 [ESR_ELx_EC_WFx] = "WFI/WFE",
799 [ESR_ELx_EC_CP15_32] = "CP15 MCR/MRC",
800 [ESR_ELx_EC_CP15_64] = "CP15 MCRR/MRRC",
801 [ESR_ELx_EC_CP14_MR] = "CP14 MCR/MRC",
802 [ESR_ELx_EC_CP14_LS] = "CP14 LDC/STC",
803 [ESR_ELx_EC_FP_ASIMD] = "ASIMD",
804 [ESR_ELx_EC_CP10_ID] = "CP10 MRC/VMRS",
805 [ESR_ELx_EC_PAC] = "PAC",
806 [ESR_ELx_EC_CP14_64] = "CP14 MCRR/MRRC",
807 [ESR_ELx_EC_BTI] = "BTI",
808 [ESR_ELx_EC_ILL] = "PSTATE.IL",
809 [ESR_ELx_EC_SVC32] = "SVC (AArch32)",
810 [ESR_ELx_EC_HVC32] = "HVC (AArch32)",
811 [ESR_ELx_EC_SMC32] = "SMC (AArch32)",
812 [ESR_ELx_EC_SVC64] = "SVC (AArch64)",
813 [ESR_ELx_EC_HVC64] = "HVC (AArch64)",
814 [ESR_ELx_EC_SMC64] = "SMC (AArch64)",
815 [ESR_ELx_EC_SYS64] = "MSR/MRS (AArch64)",
816 [ESR_ELx_EC_SVE] = "SVE",
817 [ESR_ELx_EC_ERET] = "ERET/ERETAA/ERETAB",
818 [ESR_ELx_EC_FPAC] = "FPAC",
819 [ESR_ELx_EC_IMP_DEF] = "EL3 IMP DEF",
820 [ESR_ELx_EC_IABT_LOW] = "IABT (lower EL)",
821 [ESR_ELx_EC_IABT_CUR] = "IABT (current EL)",
822 [ESR_ELx_EC_PC_ALIGN] = "PC Alignment",
823 [ESR_ELx_EC_DABT_LOW] = "DABT (lower EL)",
824 [ESR_ELx_EC_DABT_CUR] = "DABT (current EL)",
825 [ESR_ELx_EC_SP_ALIGN] = "SP Alignment",
826 [ESR_ELx_EC_FP_EXC32] = "FP (AArch32)",
827 [ESR_ELx_EC_FP_EXC64] = "FP (AArch64)",
828 [ESR_ELx_EC_SERROR] = "SError",
829 [ESR_ELx_EC_BREAKPT_LOW] = "Breakpoint (lower EL)",
830 [ESR_ELx_EC_BREAKPT_CUR] = "Breakpoint (current EL)",
831 [ESR_ELx_EC_SOFTSTP_LOW] = "Software Step (lower EL)",
832 [ESR_ELx_EC_SOFTSTP_CUR] = "Software Step (current EL)",
833 [ESR_ELx_EC_WATCHPT_LOW] = "Watchpoint (lower EL)",
834 [ESR_ELx_EC_WATCHPT_CUR] = "Watchpoint (current EL)",
835 [ESR_ELx_EC_BKPT32] = "BKPT (AArch32)",
836 [ESR_ELx_EC_VECTOR32] = "Vector catch (AArch32)",
837 [ESR_ELx_EC_BRK64] = "BRK (AArch64)",
838};
839
840const char *esr_get_class_string(u32 esr)
841{
842 return esr_class_str[ESR_ELx_EC(esr)];
843}
844
845
846
847
848
849void bad_el0_sync(struct pt_regs *regs, int reason, unsigned int esr)
850{
851 unsigned long pc = instruction_pointer(regs);
852
853 current->thread.fault_address = 0;
854 current->thread.fault_code = esr;
855
856 arm64_force_sig_fault(SIGILL, ILL_ILLOPC, pc,
857 "Bad EL0 synchronous exception");
858}
859
860#ifdef CONFIG_VMAP_STACK
861
862DEFINE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack)
863 __aligned(16);
864
865void panic_bad_stack(struct pt_regs *regs, unsigned int esr, unsigned long far)
866{
867 unsigned long tsk_stk = (unsigned long)current->stack;
868 unsigned long irq_stk = (unsigned long)this_cpu_read(irq_stack_ptr);
869 unsigned long ovf_stk = (unsigned long)this_cpu_ptr(overflow_stack);
870
871 console_verbose();
872 pr_emerg("Insufficient stack space to handle exception!");
873
874 pr_emerg("ESR: 0x%08x -- %s\n", esr, esr_get_class_string(esr));
875 pr_emerg("FAR: 0x%016lx\n", far);
876
877 pr_emerg("Task stack: [0x%016lx..0x%016lx]\n",
878 tsk_stk, tsk_stk + THREAD_SIZE);
879 pr_emerg("IRQ stack: [0x%016lx..0x%016lx]\n",
880 irq_stk, irq_stk + IRQ_STACK_SIZE);
881 pr_emerg("Overflow stack: [0x%016lx..0x%016lx]\n",
882 ovf_stk, ovf_stk + OVERFLOW_STACK_SIZE);
883
884 __show_regs(regs);
885
886
887
888
889
890 nmi_panic(NULL, "kernel stack overflow");
891 cpu_park_loop();
892}
893#endif
894
895void __noreturn arm64_serror_panic(struct pt_regs *regs, u32 esr)
896{
897 console_verbose();
898
899 pr_crit("SError Interrupt on CPU%d, code 0x%08x -- %s\n",
900 smp_processor_id(), esr, esr_get_class_string(esr));
901 if (regs)
902 __show_regs(regs);
903
904 nmi_panic(regs, "Asynchronous SError Interrupt");
905
906 cpu_park_loop();
907 unreachable();
908}
909
910bool arm64_is_fatal_ras_serror(struct pt_regs *regs, unsigned int esr)
911{
912 u32 aet = arm64_ras_serror_get_severity(esr);
913
914 switch (aet) {
915 case ESR_ELx_AET_CE:
916 case ESR_ELx_AET_UEO:
917
918
919
920
921 return false;
922
923 case ESR_ELx_AET_UEU:
924 case ESR_ELx_AET_UER:
925
926
927
928
929
930
931
932
933 return true;
934
935 case ESR_ELx_AET_UC:
936 default:
937
938 arm64_serror_panic(regs, esr);
939 }
940}
941
942void do_serror(struct pt_regs *regs, unsigned int esr)
943{
944
945 if (!arm64_is_ras_serror(esr) || arm64_is_fatal_ras_serror(regs, esr))
946 arm64_serror_panic(regs, esr);
947}
948
949
950
951int is_valid_bugaddr(unsigned long addr)
952{
953
954
955
956
957
958
959
960 return 1;
961}
962
963static int bug_handler(struct pt_regs *regs, unsigned int esr)
964{
965 switch (report_bug(regs->pc, regs)) {
966 case BUG_TRAP_TYPE_BUG:
967 die("Oops - BUG", regs, 0);
968 break;
969
970 case BUG_TRAP_TYPE_WARN:
971 break;
972
973 default:
974
975 return DBG_HOOK_ERROR;
976 }
977
978
979 arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
980 return DBG_HOOK_HANDLED;
981}
982
983static struct break_hook bug_break_hook = {
984 .fn = bug_handler,
985 .imm = BUG_BRK_IMM,
986};
987
988static int reserved_fault_handler(struct pt_regs *regs, unsigned int esr)
989{
990 pr_err("%s generated an invalid instruction at %pS!\n",
991 in_bpf_jit(regs) ? "BPF JIT" : "Kernel text patching",
992 (void *)instruction_pointer(regs));
993
994
995 return DBG_HOOK_ERROR;
996}
997
998static struct break_hook fault_break_hook = {
999 .fn = reserved_fault_handler,
1000 .imm = FAULT_BRK_IMM,
1001};
1002
1003#ifdef CONFIG_KASAN_SW_TAGS
1004
1005#define KASAN_ESR_RECOVER 0x20
1006#define KASAN_ESR_WRITE 0x10
1007#define KASAN_ESR_SIZE_MASK 0x0f
1008#define KASAN_ESR_SIZE(esr) (1 << ((esr) & KASAN_ESR_SIZE_MASK))
1009
1010static int kasan_handler(struct pt_regs *regs, unsigned int esr)
1011{
1012 bool recover = esr & KASAN_ESR_RECOVER;
1013 bool write = esr & KASAN_ESR_WRITE;
1014 size_t size = KASAN_ESR_SIZE(esr);
1015 u64 addr = regs->regs[0];
1016 u64 pc = regs->pc;
1017
1018 kasan_report(addr, size, write, pc);
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034 if (!recover)
1035 die("Oops - KASAN", regs, 0);
1036
1037
1038 arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
1039 return DBG_HOOK_HANDLED;
1040}
1041
1042static struct break_hook kasan_break_hook = {
1043 .fn = kasan_handler,
1044 .imm = KASAN_BRK_IMM,
1045 .mask = KASAN_BRK_MASK,
1046};
1047#endif
1048
1049
1050
1051
1052
1053int __init early_brk64(unsigned long addr, unsigned int esr,
1054 struct pt_regs *regs)
1055{
1056#ifdef CONFIG_KASAN_SW_TAGS
1057 unsigned int comment = esr & ESR_ELx_BRK64_ISS_COMMENT_MASK;
1058
1059 if ((comment & ~KASAN_BRK_MASK) == KASAN_BRK_IMM)
1060 return kasan_handler(regs, esr) != DBG_HOOK_HANDLED;
1061#endif
1062 return bug_handler(regs, esr) != DBG_HOOK_HANDLED;
1063}
1064
1065void __init trap_init(void)
1066{
1067 register_kernel_break_hook(&bug_break_hook);
1068 register_kernel_break_hook(&fault_break_hook);
1069#ifdef CONFIG_KASAN_SW_TAGS
1070 register_kernel_break_hook(&kasan_break_hook);
1071#endif
1072 debug_traps_init();
1073}
1074