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26#include <linux/kernel.h>
27#include <linux/sched/signal.h>
28#include <linux/sched/debug.h>
29#include <linux/sched/task_stack.h>
30#include <linux/init.h>
31#include <linux/module.h>
32#include <linux/stringify.h>
33#include <linux/kallsyms.h>
34#include <linux/delay.h>
35#include <linux/hardirq.h>
36#include <linux/ratelimit.h>
37#include <linux/pgtable.h>
38
39#include <asm/stacktrace.h>
40#include <asm/ptrace.h>
41#include <asm/timex.h>
42#include <linux/uaccess.h>
43#include <asm/processor.h>
44#include <asm/traps.h>
45#include <asm/hw_breakpoint.h>
46
47
48
49
50
51extern void kernel_exception(void);
52extern void user_exception(void);
53
54extern void fast_illegal_instruction_user(void);
55extern void fast_syscall_user(void);
56extern void fast_alloca(void);
57extern void fast_unaligned(void);
58extern void fast_second_level_miss(void);
59extern void fast_store_prohibited(void);
60extern void fast_coprocessor(void);
61
62extern void do_illegal_instruction (struct pt_regs*);
63extern void do_interrupt (struct pt_regs*);
64extern void do_nmi(struct pt_regs *);
65extern void do_unaligned_user (struct pt_regs*);
66extern void do_multihit (struct pt_regs*, unsigned long);
67extern void do_page_fault (struct pt_regs*, unsigned long);
68extern void do_debug (struct pt_regs*);
69extern void system_call (struct pt_regs*);
70
71
72
73
74
75
76
77#define KRNL 0x01
78#define USER 0x02
79
80#define COPROCESSOR(x) \
81{ EXCCAUSE_COPROCESSOR ## x ## _DISABLED, USER, fast_coprocessor }
82
83typedef struct {
84 int cause;
85 int fast;
86 void* handler;
87} dispatch_init_table_t;
88
89static dispatch_init_table_t __initdata dispatch_init_table[] = {
90
91#ifdef CONFIG_USER_ABI_CALL0_PROBE
92{ EXCCAUSE_ILLEGAL_INSTRUCTION, USER, fast_illegal_instruction_user },
93#endif
94{ EXCCAUSE_ILLEGAL_INSTRUCTION, 0, do_illegal_instruction},
95{ EXCCAUSE_SYSTEM_CALL, USER, fast_syscall_user },
96{ EXCCAUSE_SYSTEM_CALL, 0, system_call },
97
98
99{ EXCCAUSE_LEVEL1_INTERRUPT, 0, do_interrupt },
100{ EXCCAUSE_ALLOCA, USER|KRNL, fast_alloca },
101
102
103#if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION
104#ifdef CONFIG_XTENSA_UNALIGNED_USER
105{ EXCCAUSE_UNALIGNED, USER, fast_unaligned },
106#endif
107{ EXCCAUSE_UNALIGNED, 0, do_unaligned_user },
108{ EXCCAUSE_UNALIGNED, KRNL, fast_unaligned },
109#endif
110#ifdef CONFIG_MMU
111{ EXCCAUSE_ITLB_MISS, 0, do_page_fault },
112{ EXCCAUSE_ITLB_MISS, USER|KRNL, fast_second_level_miss},
113{ EXCCAUSE_ITLB_MULTIHIT, 0, do_multihit },
114{ EXCCAUSE_ITLB_PRIVILEGE, 0, do_page_fault },
115
116{ EXCCAUSE_FETCH_CACHE_ATTRIBUTE, 0, do_page_fault },
117{ EXCCAUSE_DTLB_MISS, USER|KRNL, fast_second_level_miss},
118{ EXCCAUSE_DTLB_MISS, 0, do_page_fault },
119{ EXCCAUSE_DTLB_MULTIHIT, 0, do_multihit },
120{ EXCCAUSE_DTLB_PRIVILEGE, 0, do_page_fault },
121
122{ EXCCAUSE_STORE_CACHE_ATTRIBUTE, USER|KRNL, fast_store_prohibited },
123{ EXCCAUSE_STORE_CACHE_ATTRIBUTE, 0, do_page_fault },
124{ EXCCAUSE_LOAD_CACHE_ATTRIBUTE, 0, do_page_fault },
125#endif
126
127#if XTENSA_HAVE_COPROCESSOR(0)
128COPROCESSOR(0),
129#endif
130#if XTENSA_HAVE_COPROCESSOR(1)
131COPROCESSOR(1),
132#endif
133#if XTENSA_HAVE_COPROCESSOR(2)
134COPROCESSOR(2),
135#endif
136#if XTENSA_HAVE_COPROCESSOR(3)
137COPROCESSOR(3),
138#endif
139#if XTENSA_HAVE_COPROCESSOR(4)
140COPROCESSOR(4),
141#endif
142#if XTENSA_HAVE_COPROCESSOR(5)
143COPROCESSOR(5),
144#endif
145#if XTENSA_HAVE_COPROCESSOR(6)
146COPROCESSOR(6),
147#endif
148#if XTENSA_HAVE_COPROCESSOR(7)
149COPROCESSOR(7),
150#endif
151#if XTENSA_FAKE_NMI
152{ EXCCAUSE_MAPPED_NMI, 0, do_nmi },
153#endif
154{ EXCCAUSE_MAPPED_DEBUG, 0, do_debug },
155{ -1, -1, 0 }
156
157};
158
159
160
161
162
163
164DEFINE_PER_CPU(struct exc_table, exc_table);
165DEFINE_PER_CPU(struct debug_table, debug_table);
166
167void die(const char*, struct pt_regs*, long);
168
169static inline void
170__die_if_kernel(const char *str, struct pt_regs *regs, long err)
171{
172 if (!user_mode(regs))
173 die(str, regs, err);
174}
175
176
177
178
179
180void do_unhandled(struct pt_regs *regs, unsigned long exccause)
181{
182 __die_if_kernel("Caught unhandled exception - should not happen",
183 regs, SIGKILL);
184
185
186 pr_info_ratelimited("Caught unhandled exception in '%s' "
187 "(pid = %d, pc = %#010lx) - should not happen\n"
188 "\tEXCCAUSE is %ld\n",
189 current->comm, task_pid_nr(current), regs->pc,
190 exccause);
191 force_sig(SIGILL);
192}
193
194
195
196
197
198void do_multihit(struct pt_regs *regs, unsigned long exccause)
199{
200 die("Caught multihit exception", regs, SIGKILL);
201}
202
203
204
205
206
207extern void do_IRQ(int, struct pt_regs *);
208
209#if XTENSA_FAKE_NMI
210
211#define IS_POW2(v) (((v) & ((v) - 1)) == 0)
212
213#if !(PROFILING_INTLEVEL == XCHAL_EXCM_LEVEL && \
214 IS_POW2(XTENSA_INTLEVEL_MASK(PROFILING_INTLEVEL)))
215#warning "Fake NMI is requested for PMM, but there are other IRQs at or above its level."
216#warning "Fake NMI will be used, but there will be a bugcheck if one of those IRQs fire."
217
218static inline void check_valid_nmi(void)
219{
220 unsigned intread = xtensa_get_sr(interrupt);
221 unsigned intenable = xtensa_get_sr(intenable);
222
223 BUG_ON(intread & intenable &
224 ~(XTENSA_INTLEVEL_ANDBELOW_MASK(PROFILING_INTLEVEL) ^
225 XTENSA_INTLEVEL_MASK(PROFILING_INTLEVEL) ^
226 BIT(XCHAL_PROFILING_INTERRUPT)));
227}
228
229#else
230
231static inline void check_valid_nmi(void)
232{
233}
234
235#endif
236
237irqreturn_t xtensa_pmu_irq_handler(int irq, void *dev_id);
238
239DEFINE_PER_CPU(unsigned long, nmi_count);
240
241void do_nmi(struct pt_regs *regs)
242{
243 struct pt_regs *old_regs;
244
245 if ((regs->ps & PS_INTLEVEL_MASK) < LOCKLEVEL)
246 trace_hardirqs_off();
247
248 old_regs = set_irq_regs(regs);
249 nmi_enter();
250 ++*this_cpu_ptr(&nmi_count);
251 check_valid_nmi();
252 xtensa_pmu_irq_handler(0, NULL);
253 nmi_exit();
254 set_irq_regs(old_regs);
255}
256#endif
257
258void do_interrupt(struct pt_regs *regs)
259{
260 static const unsigned int_level_mask[] = {
261 0,
262 XCHAL_INTLEVEL1_MASK,
263 XCHAL_INTLEVEL2_MASK,
264 XCHAL_INTLEVEL3_MASK,
265 XCHAL_INTLEVEL4_MASK,
266 XCHAL_INTLEVEL5_MASK,
267 XCHAL_INTLEVEL6_MASK,
268 XCHAL_INTLEVEL7_MASK,
269 };
270 struct pt_regs *old_regs;
271
272 trace_hardirqs_off();
273
274 old_regs = set_irq_regs(regs);
275 irq_enter();
276
277 for (;;) {
278 unsigned intread = xtensa_get_sr(interrupt);
279 unsigned intenable = xtensa_get_sr(intenable);
280 unsigned int_at_level = intread & intenable;
281 unsigned level;
282
283 for (level = LOCKLEVEL; level > 0; --level) {
284 if (int_at_level & int_level_mask[level]) {
285 int_at_level &= int_level_mask[level];
286 break;
287 }
288 }
289
290 if (level == 0)
291 break;
292
293 do_IRQ(__ffs(int_at_level), regs);
294 }
295
296 irq_exit();
297 set_irq_regs(old_regs);
298}
299
300
301
302
303
304void
305do_illegal_instruction(struct pt_regs *regs)
306{
307 __die_if_kernel("Illegal instruction in kernel", regs, SIGKILL);
308
309
310
311 pr_info_ratelimited("Illegal Instruction in '%s' (pid = %d, pc = %#010lx)\n",
312 current->comm, task_pid_nr(current), regs->pc);
313 force_sig(SIGILL);
314}
315
316
317
318
319
320
321
322
323
324#if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION
325void
326do_unaligned_user (struct pt_regs *regs)
327{
328 __die_if_kernel("Unhandled unaligned exception in kernel",
329 regs, SIGKILL);
330
331 current->thread.bad_vaddr = regs->excvaddr;
332 current->thread.error_code = -3;
333 pr_info_ratelimited("Unaligned memory access to %08lx in '%s' "
334 "(pid = %d, pc = %#010lx)\n",
335 regs->excvaddr, current->comm,
336 task_pid_nr(current), regs->pc);
337 force_sig_fault(SIGBUS, BUS_ADRALN, (void *) regs->excvaddr);
338}
339#endif
340
341
342
343
344
345
346
347void
348do_debug(struct pt_regs *regs)
349{
350#ifdef CONFIG_HAVE_HW_BREAKPOINT
351 int ret = check_hw_breakpoint(regs);
352
353 preempt_enable();
354 if (ret == 0)
355 return;
356#endif
357 __die_if_kernel("Breakpoint in kernel", regs, SIGKILL);
358
359
360
361 force_sig(SIGTRAP);
362}
363
364
365#define set_handler(type, cause, handler) \
366 do { \
367 unsigned int cpu; \
368 \
369 for_each_possible_cpu(cpu) \
370 per_cpu(exc_table, cpu).type[cause] = (handler);\
371 } while (0)
372
373
374
375void * __init trap_set_handler(int cause, void *handler)
376{
377 void *previous = per_cpu(exc_table, 0).default_handler[cause];
378
379 set_handler(default_handler, cause, handler);
380 return previous;
381}
382
383
384static void trap_init_excsave(void)
385{
386 unsigned long excsave1 = (unsigned long)this_cpu_ptr(&exc_table);
387 __asm__ __volatile__("wsr %0, excsave1\n" : : "a" (excsave1));
388}
389
390static void trap_init_debug(void)
391{
392 unsigned long debugsave = (unsigned long)this_cpu_ptr(&debug_table);
393
394 this_cpu_ptr(&debug_table)->debug_exception = debug_exception;
395 __asm__ __volatile__("wsr %0, excsave" __stringify(XCHAL_DEBUGLEVEL)
396 :: "a"(debugsave));
397}
398
399
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401
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403
404
405
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407
408
409
410
411
412void __init trap_init(void)
413{
414 int i;
415
416
417
418 for (i = 0; i < EXCCAUSE_N; i++) {
419 set_handler(fast_user_handler, i, user_exception);
420 set_handler(fast_kernel_handler, i, kernel_exception);
421 set_handler(default_handler, i, do_unhandled);
422 }
423
424
425
426 for(i = 0; dispatch_init_table[i].cause >= 0; i++) {
427 int fast = dispatch_init_table[i].fast;
428 int cause = dispatch_init_table[i].cause;
429 void *handler = dispatch_init_table[i].handler;
430
431 if (fast == 0)
432 set_handler(default_handler, cause, handler);
433 if ((fast & USER) != 0)
434 set_handler(fast_user_handler, cause, handler);
435 if ((fast & KRNL) != 0)
436 set_handler(fast_kernel_handler, cause, handler);
437 }
438
439
440 trap_init_excsave();
441 trap_init_debug();
442}
443
444#ifdef CONFIG_SMP
445void secondary_trap_init(void)
446{
447 trap_init_excsave();
448 trap_init_debug();
449}
450#endif
451
452
453
454
455
456void show_regs(struct pt_regs * regs)
457{
458 int i, wmask;
459
460 show_regs_print_info(KERN_DEFAULT);
461
462 wmask = regs->wmask & ~1;
463
464 for (i = 0; i < 16; i++) {
465 if ((i % 8) == 0)
466 pr_info("a%02d:", i);
467 pr_cont(" %08lx", regs->areg[i]);
468 }
469 pr_cont("\n");
470 pr_info("pc: %08lx, ps: %08lx, depc: %08lx, excvaddr: %08lx\n",
471 regs->pc, regs->ps, regs->depc, regs->excvaddr);
472 pr_info("lbeg: %08lx, lend: %08lx lcount: %08lx, sar: %08lx\n",
473 regs->lbeg, regs->lend, regs->lcount, regs->sar);
474 if (user_mode(regs))
475 pr_cont("wb: %08lx, ws: %08lx, wmask: %08lx, syscall: %ld\n",
476 regs->windowbase, regs->windowstart, regs->wmask,
477 regs->syscall);
478}
479
480static int show_trace_cb(struct stackframe *frame, void *data)
481{
482 const char *loglvl = data;
483
484 if (kernel_text_address(frame->pc))
485 printk("%s [<%08lx>] %pB\n",
486 loglvl, frame->pc, (void *)frame->pc);
487 return 0;
488}
489
490static void show_trace(struct task_struct *task, unsigned long *sp,
491 const char *loglvl)
492{
493 if (!sp)
494 sp = stack_pointer(task);
495
496 printk("%sCall Trace:\n", loglvl);
497 walk_stackframe(sp, show_trace_cb, (void *)loglvl);
498}
499
500#define STACK_DUMP_ENTRY_SIZE 4
501#define STACK_DUMP_LINE_SIZE 32
502static size_t kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH;
503
504void show_stack(struct task_struct *task, unsigned long *sp, const char *loglvl)
505{
506 size_t len;
507
508 if (!sp)
509 sp = stack_pointer(task);
510
511 len = min((-(size_t)sp) & (THREAD_SIZE - STACK_DUMP_ENTRY_SIZE),
512 kstack_depth_to_print * STACK_DUMP_ENTRY_SIZE);
513
514 printk("%sStack:\n", loglvl);
515 print_hex_dump(loglvl, " ", DUMP_PREFIX_NONE,
516 STACK_DUMP_LINE_SIZE, STACK_DUMP_ENTRY_SIZE,
517 sp, len, false);
518 show_trace(task, sp, loglvl);
519}
520
521DEFINE_SPINLOCK(die_lock);
522
523void die(const char * str, struct pt_regs * regs, long err)
524{
525 static int die_counter;
526 const char *pr = "";
527
528 if (IS_ENABLED(CONFIG_PREEMPTION))
529 pr = IS_ENABLED(CONFIG_PREEMPT_RT) ? " PREEMPT_RT" : " PREEMPT";
530
531 console_verbose();
532 spin_lock_irq(&die_lock);
533
534 pr_info("%s: sig: %ld [#%d]%s\n", str, err, ++die_counter, pr);
535 show_regs(regs);
536 if (!user_mode(regs))
537 show_stack(NULL, (unsigned long *)regs->areg[1], KERN_INFO);
538
539 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
540 spin_unlock_irq(&die_lock);
541
542 if (in_interrupt())
543 panic("Fatal exception in interrupt");
544
545 if (panic_on_oops)
546 panic("Fatal exception");
547
548 do_exit(err);
549}
550
