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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
38#include <asm/stacktrace.h>
39#include <asm/ptrace.h>
40#include <asm/timex.h>
41#include <linux/uaccess.h>
42#include <asm/pgtable.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_syscall_kernel(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{ EXCCAUSE_ILLEGAL_INSTRUCTION, 0, do_illegal_instruction},
92{ EXCCAUSE_SYSTEM_CALL, KRNL, fast_syscall_kernel },
93{ EXCCAUSE_SYSTEM_CALL, USER, fast_syscall_user },
94{ EXCCAUSE_SYSTEM_CALL, 0, system_call },
95
96
97{ EXCCAUSE_LEVEL1_INTERRUPT, 0, do_interrupt },
98{ EXCCAUSE_ALLOCA, USER|KRNL, fast_alloca },
99
100
101#if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION
102#ifdef CONFIG_XTENSA_UNALIGNED_USER
103{ EXCCAUSE_UNALIGNED, USER, fast_unaligned },
104#endif
105{ EXCCAUSE_UNALIGNED, 0, do_unaligned_user },
106{ EXCCAUSE_UNALIGNED, KRNL, fast_unaligned },
107#endif
108#ifdef CONFIG_MMU
109{ EXCCAUSE_ITLB_MISS, 0, do_page_fault },
110{ EXCCAUSE_ITLB_MISS, USER|KRNL, fast_second_level_miss},
111{ EXCCAUSE_ITLB_MULTIHIT, 0, do_multihit },
112{ EXCCAUSE_ITLB_PRIVILEGE, 0, do_page_fault },
113
114{ EXCCAUSE_FETCH_CACHE_ATTRIBUTE, 0, do_page_fault },
115{ EXCCAUSE_DTLB_MISS, USER|KRNL, fast_second_level_miss},
116{ EXCCAUSE_DTLB_MISS, 0, do_page_fault },
117{ EXCCAUSE_DTLB_MULTIHIT, 0, do_multihit },
118{ EXCCAUSE_DTLB_PRIVILEGE, 0, do_page_fault },
119
120{ EXCCAUSE_STORE_CACHE_ATTRIBUTE, USER|KRNL, fast_store_prohibited },
121{ EXCCAUSE_STORE_CACHE_ATTRIBUTE, 0, do_page_fault },
122{ EXCCAUSE_LOAD_CACHE_ATTRIBUTE, 0, do_page_fault },
123#endif
124
125#if XTENSA_HAVE_COPROCESSOR(0)
126COPROCESSOR(0),
127#endif
128#if XTENSA_HAVE_COPROCESSOR(1)
129COPROCESSOR(1),
130#endif
131#if XTENSA_HAVE_COPROCESSOR(2)
132COPROCESSOR(2),
133#endif
134#if XTENSA_HAVE_COPROCESSOR(3)
135COPROCESSOR(3),
136#endif
137#if XTENSA_HAVE_COPROCESSOR(4)
138COPROCESSOR(4),
139#endif
140#if XTENSA_HAVE_COPROCESSOR(5)
141COPROCESSOR(5),
142#endif
143#if XTENSA_HAVE_COPROCESSOR(6)
144COPROCESSOR(6),
145#endif
146#if XTENSA_HAVE_COPROCESSOR(7)
147COPROCESSOR(7),
148#endif
149#if XTENSA_FAKE_NMI
150{ EXCCAUSE_MAPPED_NMI, 0, do_nmi },
151#endif
152{ EXCCAUSE_MAPPED_DEBUG, 0, do_debug },
153{ -1, -1, 0 }
154
155};
156
157
158
159
160
161
162DEFINE_PER_CPU(struct exc_table, exc_table);
163DEFINE_PER_CPU(struct debug_table, debug_table);
164
165void die(const char*, struct pt_regs*, long);
166
167static inline void
168__die_if_kernel(const char *str, struct pt_regs *regs, long err)
169{
170 if (!user_mode(regs))
171 die(str, regs, err);
172}
173
174
175
176
177
178void do_unhandled(struct pt_regs *regs, unsigned long exccause)
179{
180 __die_if_kernel("Caught unhandled exception - should not happen",
181 regs, SIGKILL);
182
183
184 pr_info_ratelimited("Caught unhandled exception in '%s' "
185 "(pid = %d, pc = %#010lx) - should not happen\n"
186 "\tEXCCAUSE is %ld\n",
187 current->comm, task_pid_nr(current), regs->pc,
188 exccause);
189 force_sig(SIGILL, current);
190}
191
192
193
194
195
196void do_multihit(struct pt_regs *regs, unsigned long exccause)
197{
198 die("Caught multihit exception", regs, SIGKILL);
199}
200
201
202
203
204
205extern void do_IRQ(int, struct pt_regs *);
206
207#if XTENSA_FAKE_NMI
208
209#define IS_POW2(v) (((v) & ((v) - 1)) == 0)
210
211#if !(PROFILING_INTLEVEL == XCHAL_EXCM_LEVEL && \
212 IS_POW2(XTENSA_INTLEVEL_MASK(PROFILING_INTLEVEL)))
213#warning "Fake NMI is requested for PMM, but there are other IRQs at or above its level."
214#warning "Fake NMI will be used, but there will be a bugcheck if one of those IRQs fire."
215
216static inline void check_valid_nmi(void)
217{
218 unsigned intread = get_sr(interrupt);
219 unsigned intenable = get_sr(intenable);
220
221 BUG_ON(intread & intenable &
222 ~(XTENSA_INTLEVEL_ANDBELOW_MASK(PROFILING_INTLEVEL) ^
223 XTENSA_INTLEVEL_MASK(PROFILING_INTLEVEL) ^
224 BIT(XCHAL_PROFILING_INTERRUPT)));
225}
226
227#else
228
229static inline void check_valid_nmi(void)
230{
231}
232
233#endif
234
235irqreturn_t xtensa_pmu_irq_handler(int irq, void *dev_id);
236
237DEFINE_PER_CPU(unsigned long, nmi_count);
238
239void do_nmi(struct pt_regs *regs)
240{
241 struct pt_regs *old_regs;
242
243 if ((regs->ps & PS_INTLEVEL_MASK) < LOCKLEVEL)
244 trace_hardirqs_off();
245
246 old_regs = set_irq_regs(regs);
247 nmi_enter();
248 ++*this_cpu_ptr(&nmi_count);
249 check_valid_nmi();
250 xtensa_pmu_irq_handler(0, NULL);
251 nmi_exit();
252 set_irq_regs(old_regs);
253}
254#endif
255
256void do_interrupt(struct pt_regs *regs)
257{
258 static const unsigned int_level_mask[] = {
259 0,
260 XCHAL_INTLEVEL1_MASK,
261 XCHAL_INTLEVEL2_MASK,
262 XCHAL_INTLEVEL3_MASK,
263 XCHAL_INTLEVEL4_MASK,
264 XCHAL_INTLEVEL5_MASK,
265 XCHAL_INTLEVEL6_MASK,
266 XCHAL_INTLEVEL7_MASK,
267 };
268 struct pt_regs *old_regs;
269
270 trace_hardirqs_off();
271
272 old_regs = set_irq_regs(regs);
273 irq_enter();
274
275 for (;;) {
276 unsigned intread = get_sr(interrupt);
277 unsigned intenable = get_sr(intenable);
278 unsigned int_at_level = intread & intenable;
279 unsigned level;
280
281 for (level = LOCKLEVEL; level > 0; --level) {
282 if (int_at_level & int_level_mask[level]) {
283 int_at_level &= int_level_mask[level];
284 break;
285 }
286 }
287
288 if (level == 0)
289 break;
290
291 do_IRQ(__ffs(int_at_level), regs);
292 }
293
294 irq_exit();
295 set_irq_regs(old_regs);
296}
297
298
299
300
301
302void
303do_illegal_instruction(struct pt_regs *regs)
304{
305 __die_if_kernel("Illegal instruction in kernel", regs, SIGKILL);
306
307
308
309 pr_info_ratelimited("Illegal Instruction in '%s' (pid = %d, pc = %#010lx)\n",
310 current->comm, task_pid_nr(current), regs->pc);
311 force_sig(SIGILL, current);
312}
313
314
315
316
317
318
319
320
321
322#if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION
323void
324do_unaligned_user (struct pt_regs *regs)
325{
326 __die_if_kernel("Unhandled unaligned exception in kernel",
327 regs, SIGKILL);
328
329 current->thread.bad_vaddr = regs->excvaddr;
330 current->thread.error_code = -3;
331 pr_info_ratelimited("Unaligned memory access to %08lx in '%s' "
332 "(pid = %d, pc = %#010lx)\n",
333 regs->excvaddr, current->comm,
334 task_pid_nr(current), regs->pc);
335 force_sig_fault(SIGBUS, BUS_ADRALN, (void *) regs->excvaddr, current);
336}
337#endif
338
339
340
341
342
343
344
345void
346do_debug(struct pt_regs *regs)
347{
348#ifdef CONFIG_HAVE_HW_BREAKPOINT
349 int ret = check_hw_breakpoint(regs);
350
351 preempt_enable();
352 if (ret == 0)
353 return;
354#endif
355 __die_if_kernel("Breakpoint in kernel", regs, SIGKILL);
356
357
358
359 force_sig(SIGTRAP, current);
360}
361
362
363#define set_handler(type, cause, handler) \
364 do { \
365 unsigned int cpu; \
366 \
367 for_each_possible_cpu(cpu) \
368 per_cpu(exc_table, cpu).type[cause] = (handler);\
369 } while (0)
370
371
372
373void * __init trap_set_handler(int cause, void *handler)
374{
375 void *previous = per_cpu(exc_table, 0).default_handler[cause];
376
377 set_handler(default_handler, cause, handler);
378 return previous;
379}
380
381
382static void trap_init_excsave(void)
383{
384 unsigned long excsave1 = (unsigned long)this_cpu_ptr(&exc_table);
385 __asm__ __volatile__("wsr %0, excsave1\n" : : "a" (excsave1));
386}
387
388static void trap_init_debug(void)
389{
390 unsigned long debugsave = (unsigned long)this_cpu_ptr(&debug_table);
391
392 this_cpu_ptr(&debug_table)->debug_exception = debug_exception;
393 __asm__ __volatile__("wsr %0, excsave" __stringify(XCHAL_DEBUGLEVEL)
394 :: "a"(debugsave));
395}
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410void __init trap_init(void)
411{
412 int i;
413
414
415
416 for (i = 0; i < EXCCAUSE_N; i++) {
417 set_handler(fast_user_handler, i, user_exception);
418 set_handler(fast_kernel_handler, i, kernel_exception);
419 set_handler(default_handler, i, do_unhandled);
420 }
421
422
423
424 for(i = 0; dispatch_init_table[i].cause >= 0; i++) {
425
426 int fast = dispatch_init_table[i].fast;
427 int cause = dispatch_init_table[i].cause;
428 void *handler = dispatch_init_table[i].handler;
429
430 if (fast == 0)
431 set_handler(default_handler, cause, handler);
432 if (fast && fast & USER)
433 set_handler(fast_user_handler, cause, handler);
434 if (fast && fast & KRNL)
435 set_handler(fast_kernel_handler, cause, handler);
436 }
437
438
439 trap_init_excsave();
440 trap_init_debug();
441}
442
443#ifdef CONFIG_SMP
444void secondary_trap_init(void)
445{
446 trap_init_excsave();
447 trap_init_debug();
448}
449#endif
450
451
452
453
454
455void show_regs(struct pt_regs * regs)
456{
457 int i, wmask;
458
459 show_regs_print_info(KERN_DEFAULT);
460
461 wmask = regs->wmask & ~1;
462
463 for (i = 0; i < 16; i++) {
464 if ((i % 8) == 0)
465 pr_info("a%02d:", i);
466 pr_cont(" %08lx", regs->areg[i]);
467 }
468 pr_cont("\n");
469 pr_info("pc: %08lx, ps: %08lx, depc: %08lx, excvaddr: %08lx\n",
470 regs->pc, regs->ps, regs->depc, regs->excvaddr);
471 pr_info("lbeg: %08lx, lend: %08lx lcount: %08lx, sar: %08lx\n",
472 regs->lbeg, regs->lend, regs->lcount, regs->sar);
473 if (user_mode(regs))
474 pr_cont("wb: %08lx, ws: %08lx, wmask: %08lx, syscall: %ld\n",
475 regs->windowbase, regs->windowstart, regs->wmask,
476 regs->syscall);
477}
478
479static int show_trace_cb(struct stackframe *frame, void *data)
480{
481 if (kernel_text_address(frame->pc))
482 pr_cont(" [<%08lx>] %pB\n", frame->pc, (void *)frame->pc);
483 return 0;
484}
485
486void show_trace(struct task_struct *task, unsigned long *sp)
487{
488 if (!sp)
489 sp = stack_pointer(task);
490
491 pr_info("Call Trace:\n");
492 walk_stackframe(sp, show_trace_cb, NULL);
493#ifndef CONFIG_KALLSYMS
494 pr_cont("\n");
495#endif
496}
497
498static int kstack_depth_to_print = 24;
499
500void show_stack(struct task_struct *task, unsigned long *sp)
501{
502 int i = 0;
503 unsigned long *stack;
504
505 if (!sp)
506 sp = stack_pointer(task);
507 stack = sp;
508
509 pr_info("Stack:\n");
510
511 for (i = 0; i < kstack_depth_to_print; i++) {
512 if (kstack_end(sp))
513 break;
514 pr_cont(" %08lx", *sp++);
515 if (i % 8 == 7)
516 pr_cont("\n");
517 }
518 show_trace(task, stack);
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
527 console_verbose();
528 spin_lock_irq(&die_lock);
529
530 pr_info("%s: sig: %ld [#%d]%s\n", str, err, ++die_counter,
531 IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "");
532 show_regs(regs);
533 if (!user_mode(regs))
534 show_stack(NULL, (unsigned long*)regs->areg[1]);
535
536 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
537 spin_unlock_irq(&die_lock);
538
539 if (in_interrupt())
540 panic("Fatal exception in interrupt");
541
542 if (panic_on_oops)
543 panic("Fatal exception");
544
545 do_exit(err);
546}
547
