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13#include <linux/sched.h>
14#include <linux/module.h>
15#include <linux/memblock.h>
16#include <linux/sort.h>
17#include <linux/slab.h>
18#include <linux/stop_machine.h>
19#include <linux/uaccess.h>
20#include <linux/ptrace.h>
21#include <asm/sections.h>
22#include <asm/unaligned.h>
23#include <asm/unwind.h>
24
25extern char __start_unwind[], __end_unwind[];
26
27
28
29
30#ifdef UNWIND_DEBUG
31int dbg_unw;
32#define unw_debug(fmt, ...) \
33do { \
34 if (dbg_unw) \
35 pr_info(fmt, ##__VA_ARGS__); \
36} while (0);
37#else
38#define unw_debug(fmt, ...)
39#endif
40
41#define MAX_STACK_DEPTH 8
42
43#define EXTRA_INFO(f) { \
44 BUILD_BUG_ON_ZERO(offsetof(struct unwind_frame_info, f) \
45 % sizeof_field(struct unwind_frame_info, f)) \
46 + offsetof(struct unwind_frame_info, f) \
47 / sizeof_field(struct unwind_frame_info, f), \
48 sizeof_field(struct unwind_frame_info, f) \
49 }
50#define PTREGS_INFO(f) EXTRA_INFO(regs.f)
51
52static const struct {
53 unsigned offs:BITS_PER_LONG / 2;
54 unsigned width:BITS_PER_LONG / 2;
55} reg_info[] = {
56UNW_REGISTER_INFO};
57
58#undef PTREGS_INFO
59#undef EXTRA_INFO
60
61#ifndef REG_INVALID
62#define REG_INVALID(r) (reg_info[r].width == 0)
63#endif
64
65#define DW_CFA_nop 0x00
66#define DW_CFA_set_loc 0x01
67#define DW_CFA_advance_loc1 0x02
68#define DW_CFA_advance_loc2 0x03
69#define DW_CFA_advance_loc4 0x04
70#define DW_CFA_offset_extended 0x05
71#define DW_CFA_restore_extended 0x06
72#define DW_CFA_undefined 0x07
73#define DW_CFA_same_value 0x08
74#define DW_CFA_register 0x09
75#define DW_CFA_remember_state 0x0a
76#define DW_CFA_restore_state 0x0b
77#define DW_CFA_def_cfa 0x0c
78#define DW_CFA_def_cfa_register 0x0d
79#define DW_CFA_def_cfa_offset 0x0e
80#define DW_CFA_def_cfa_expression 0x0f
81#define DW_CFA_expression 0x10
82#define DW_CFA_offset_extended_sf 0x11
83#define DW_CFA_def_cfa_sf 0x12
84#define DW_CFA_def_cfa_offset_sf 0x13
85#define DW_CFA_val_offset 0x14
86#define DW_CFA_val_offset_sf 0x15
87#define DW_CFA_val_expression 0x16
88#define DW_CFA_lo_user 0x1c
89#define DW_CFA_GNU_window_save 0x2d
90#define DW_CFA_GNU_args_size 0x2e
91#define DW_CFA_GNU_negative_offset_extended 0x2f
92#define DW_CFA_hi_user 0x3f
93
94#define DW_EH_PE_FORM 0x07
95#define DW_EH_PE_native 0x00
96#define DW_EH_PE_leb128 0x01
97#define DW_EH_PE_data2 0x02
98#define DW_EH_PE_data4 0x03
99#define DW_EH_PE_data8 0x04
100#define DW_EH_PE_signed 0x08
101#define DW_EH_PE_ADJUST 0x70
102#define DW_EH_PE_abs 0x00
103#define DW_EH_PE_pcrel 0x10
104#define DW_EH_PE_textrel 0x20
105#define DW_EH_PE_datarel 0x30
106#define DW_EH_PE_funcrel 0x40
107#define DW_EH_PE_aligned 0x50
108#define DW_EH_PE_indirect 0x80
109#define DW_EH_PE_omit 0xff
110
111#define CIE_ID 0
112
113typedef unsigned long uleb128_t;
114typedef signed long sleb128_t;
115
116static struct unwind_table {
117 struct {
118 unsigned long pc;
119 unsigned long range;
120 } core, init;
121 const void *address;
122 unsigned long size;
123 const unsigned char *header;
124 unsigned long hdrsz;
125 struct unwind_table *link;
126 const char *name;
127} root_table;
128
129struct unwind_item {
130 enum item_location {
131 Nowhere,
132 Memory,
133 Register,
134 Value
135 } where;
136 uleb128_t value;
137};
138
139struct unwind_state {
140 uleb128_t loc, org;
141 const u8 *cieStart, *cieEnd;
142 uleb128_t codeAlign;
143 sleb128_t dataAlign;
144 struct cfa {
145 uleb128_t reg, offs;
146 } cfa;
147 struct unwind_item regs[ARRAY_SIZE(reg_info)];
148 unsigned stackDepth:8;
149 unsigned version:8;
150 const u8 *label;
151 const u8 *stack[MAX_STACK_DEPTH];
152};
153
154static const struct cfa badCFA = { ARRAY_SIZE(reg_info), 1 };
155
156static struct unwind_table *find_table(unsigned long pc)
157{
158 struct unwind_table *table;
159
160 for (table = &root_table; table; table = table->link)
161 if ((pc >= table->core.pc
162 && pc < table->core.pc + table->core.range)
163 || (pc >= table->init.pc
164 && pc < table->init.pc + table->init.range))
165 break;
166
167 return table;
168}
169
170static unsigned long read_pointer(const u8 **pLoc,
171 const void *end, signed ptrType);
172static void init_unwind_hdr(struct unwind_table *table,
173 void *(*alloc) (unsigned long));
174
175
176
177
178
179static void *__init unw_hdr_alloc_early(unsigned long sz)
180{
181 return memblock_alloc_from(sz, sizeof(unsigned int), MAX_DMA_ADDRESS);
182}
183
184static void init_unwind_table(struct unwind_table *table, const char *name,
185 const void *core_start, unsigned long core_size,
186 const void *init_start, unsigned long init_size,
187 const void *table_start, unsigned long table_size,
188 const u8 *header_start, unsigned long header_size)
189{
190 table->core.pc = (unsigned long)core_start;
191 table->core.range = core_size;
192 table->init.pc = (unsigned long)init_start;
193 table->init.range = init_size;
194 table->address = table_start;
195 table->size = table_size;
196
197 if (header_start != NULL) {
198 const u8 *ptr = header_start + 4;
199 const u8 *end = header_start + header_size;
200
201 if (header_size <= 4
202 || header_start[0] != 1
203 || (void *)read_pointer(&ptr, end, header_start[1])
204 != table_start
205 || header_start[2] == DW_EH_PE_omit
206 || read_pointer(&ptr, end, header_start[2]) <= 0
207 || header_start[3] == DW_EH_PE_omit)
208 header_start = NULL;
209 }
210 table->hdrsz = header_size;
211 smp_wmb();
212 table->header = header_start;
213 table->link = NULL;
214 table->name = name;
215}
216
217void __init arc_unwind_init(void)
218{
219 init_unwind_table(&root_table, "kernel", _text, _end - _text, NULL, 0,
220 __start_unwind, __end_unwind - __start_unwind,
221 NULL, 0);
222
223
224 init_unwind_hdr(&root_table, unw_hdr_alloc_early);
225}
226
227static const u32 bad_cie, not_fde;
228static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *);
229static const u32 *__cie_for_fde(const u32 *fde);
230static signed fde_pointer_type(const u32 *cie);
231
232struct eh_frame_hdr_table_entry {
233 unsigned long start, fde;
234};
235
236static int cmp_eh_frame_hdr_table_entries(const void *p1, const void *p2)
237{
238 const struct eh_frame_hdr_table_entry *e1 = p1;
239 const struct eh_frame_hdr_table_entry *e2 = p2;
240
241 return (e1->start > e2->start) - (e1->start < e2->start);
242}
243
244static void swap_eh_frame_hdr_table_entries(void *p1, void *p2, int size)
245{
246 struct eh_frame_hdr_table_entry *e1 = p1;
247 struct eh_frame_hdr_table_entry *e2 = p2;
248 unsigned long v;
249
250 v = e1->start;
251 e1->start = e2->start;
252 e2->start = v;
253 v = e1->fde;
254 e1->fde = e2->fde;
255 e2->fde = v;
256}
257
258static void init_unwind_hdr(struct unwind_table *table,
259 void *(*alloc) (unsigned long))
260{
261 const u8 *ptr;
262 unsigned long tableSize = table->size, hdrSize;
263 unsigned int n;
264 const u32 *fde;
265 struct {
266 u8 version;
267 u8 eh_frame_ptr_enc;
268 u8 fde_count_enc;
269 u8 table_enc;
270 unsigned long eh_frame_ptr;
271 unsigned int fde_count;
272 struct eh_frame_hdr_table_entry table[];
273 } __attribute__ ((__packed__)) *header;
274
275 if (table->header)
276 return;
277
278 if (table->hdrsz)
279 pr_warn(".eh_frame_hdr for '%s' present but unusable\n",
280 table->name);
281
282 if (tableSize & (sizeof(*fde) - 1))
283 return;
284
285 for (fde = table->address, n = 0;
286 tableSize > sizeof(*fde) && tableSize - sizeof(*fde) >= *fde;
287 tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) {
288 const u32 *cie = cie_for_fde(fde, table);
289 signed ptrType;
290
291 if (cie == ¬_fde)
292 continue;
293 if (cie == NULL || cie == &bad_cie)
294 goto ret_err;
295 ptrType = fde_pointer_type(cie);
296 if (ptrType < 0)
297 goto ret_err;
298
299 ptr = (const u8 *)(fde + 2);
300 if (!read_pointer(&ptr, (const u8 *)(fde + 1) + *fde,
301 ptrType)) {
302
303
304
305
306 WARN(1, "unwinder: FDE->initial_location NULL %p\n",
307 (const u8 *)(fde + 1) + *fde);
308 }
309 ++n;
310 }
311
312 if (tableSize || !n)
313 goto ret_err;
314
315 hdrSize = 4 + sizeof(unsigned long) + sizeof(unsigned int)
316 + 2 * n * sizeof(unsigned long);
317
318 header = alloc(hdrSize);
319 if (!header)
320 goto ret_err;
321
322 header->version = 1;
323 header->eh_frame_ptr_enc = DW_EH_PE_abs | DW_EH_PE_native;
324 header->fde_count_enc = DW_EH_PE_abs | DW_EH_PE_data4;
325 header->table_enc = DW_EH_PE_abs | DW_EH_PE_native;
326 put_unaligned((unsigned long)table->address, &header->eh_frame_ptr);
327 BUILD_BUG_ON(offsetof(typeof(*header), fde_count)
328 % __alignof(typeof(header->fde_count)));
329 header->fde_count = n;
330
331 BUILD_BUG_ON(offsetof(typeof(*header), table)
332 % __alignof(typeof(*header->table)));
333 for (fde = table->address, tableSize = table->size, n = 0;
334 tableSize;
335 tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) {
336 const u32 *cie = __cie_for_fde(fde);
337
338 if (fde[1] == CIE_ID)
339 continue;
340 ptr = (const u8 *)(fde + 2);
341 header->table[n].start = read_pointer(&ptr,
342 (const u8 *)(fde + 1) +
343 *fde,
344 fde_pointer_type(cie));
345 header->table[n].fde = (unsigned long)fde;
346 ++n;
347 }
348 WARN_ON(n != header->fde_count);
349
350 sort(header->table,
351 n,
352 sizeof(*header->table),
353 cmp_eh_frame_hdr_table_entries, swap_eh_frame_hdr_table_entries);
354
355 table->hdrsz = hdrSize;
356 smp_wmb();
357 table->header = (const void *)header;
358 return;
359
360ret_err:
361 panic("Attention !!! Dwarf FDE parsing errors\n");
362}
363
364#ifdef CONFIG_MODULES
365static void *unw_hdr_alloc(unsigned long sz)
366{
367 return kmalloc(sz, GFP_KERNEL);
368}
369
370static struct unwind_table *last_table;
371
372
373void *unwind_add_table(struct module *module, const void *table_start,
374 unsigned long table_size)
375{
376 struct unwind_table *table;
377
378 if (table_size <= 0)
379 return NULL;
380
381 table = kmalloc(sizeof(*table), GFP_KERNEL);
382 if (!table)
383 return NULL;
384
385 init_unwind_table(table, module->name,
386 module->core_layout.base, module->core_layout.size,
387 module->init_layout.base, module->init_layout.size,
388 table_start, table_size,
389 NULL, 0);
390
391 init_unwind_hdr(table, unw_hdr_alloc);
392
393#ifdef UNWIND_DEBUG
394 unw_debug("Table added for [%s] %lx %lx\n",
395 module->name, table->core.pc, table->core.range);
396#endif
397 if (last_table)
398 last_table->link = table;
399 else
400 root_table.link = table;
401 last_table = table;
402
403 return table;
404}
405
406struct unlink_table_info {
407 struct unwind_table *table;
408 int init_only;
409};
410
411static int unlink_table(void *arg)
412{
413 struct unlink_table_info *info = arg;
414 struct unwind_table *table = info->table, *prev;
415
416 for (prev = &root_table; prev->link && prev->link != table;
417 prev = prev->link)
418 ;
419
420 if (prev->link) {
421 if (info->init_only) {
422 table->init.pc = 0;
423 table->init.range = 0;
424 info->table = NULL;
425 } else {
426 prev->link = table->link;
427 if (!prev->link)
428 last_table = prev;
429 }
430 } else
431 info->table = NULL;
432
433 return 0;
434}
435
436
437void unwind_remove_table(void *handle, int init_only)
438{
439 struct unwind_table *table = handle;
440 struct unlink_table_info info;
441
442 if (!table || table == &root_table)
443 return;
444
445 if (init_only && table == last_table) {
446 table->init.pc = 0;
447 table->init.range = 0;
448 return;
449 }
450
451 info.table = table;
452 info.init_only = init_only;
453
454 unlink_table(&info);
455 kfree(table->header);
456 kfree(table);
457}
458
459#endif
460
461static uleb128_t get_uleb128(const u8 **pcur, const u8 *end)
462{
463 const u8 *cur = *pcur;
464 uleb128_t value;
465 unsigned int shift;
466
467 for (shift = 0, value = 0; cur < end; shift += 7) {
468 if (shift + 7 > 8 * sizeof(value)
469 && (*cur & 0x7fU) >= (1U << (8 * sizeof(value) - shift))) {
470 cur = end + 1;
471 break;
472 }
473 value |= (uleb128_t) (*cur & 0x7f) << shift;
474 if (!(*cur++ & 0x80))
475 break;
476 }
477 *pcur = cur;
478
479 return value;
480}
481
482static sleb128_t get_sleb128(const u8 **pcur, const u8 *end)
483{
484 const u8 *cur = *pcur;
485 sleb128_t value;
486 unsigned int shift;
487
488 for (shift = 0, value = 0; cur < end; shift += 7) {
489 if (shift + 7 > 8 * sizeof(value)
490 && (*cur & 0x7fU) >= (1U << (8 * sizeof(value) - shift))) {
491 cur = end + 1;
492 break;
493 }
494 value |= (sleb128_t) (*cur & 0x7f) << shift;
495 if (!(*cur & 0x80)) {
496 value |= -(*cur++ & 0x40) << shift;
497 break;
498 }
499 }
500 *pcur = cur;
501
502 return value;
503}
504
505static const u32 *__cie_for_fde(const u32 *fde)
506{
507 const u32 *cie;
508
509 cie = fde + 1 - fde[1] / sizeof(*fde);
510
511 return cie;
512}
513
514static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *table)
515{
516 const u32 *cie;
517
518 if (!*fde || (*fde & (sizeof(*fde) - 1)))
519 return &bad_cie;
520
521 if (fde[1] == CIE_ID)
522 return ¬_fde;
523
524 if ((fde[1] & (sizeof(*fde) - 1)))
525
526 return NULL;
527
528 cie = __cie_for_fde(fde);
529
530 if (*cie <= sizeof(*cie) + 4 || *cie >= fde[1] - sizeof(*fde)
531 || (*cie & (sizeof(*cie) - 1))
532 || (cie[1] != CIE_ID))
533 return NULL;
534 return cie;
535}
536
537static unsigned long read_pointer(const u8 **pLoc, const void *end,
538 signed ptrType)
539{
540 unsigned long value = 0;
541 union {
542 const u8 *p8;
543 const u16 *p16u;
544 const s16 *p16s;
545 const u32 *p32u;
546 const s32 *p32s;
547 const unsigned long *pul;
548 } ptr;
549
550 if (ptrType < 0 || ptrType == DW_EH_PE_omit)
551 return 0;
552 ptr.p8 = *pLoc;
553 switch (ptrType & DW_EH_PE_FORM) {
554 case DW_EH_PE_data2:
555 if (end < (const void *)(ptr.p16u + 1))
556 return 0;
557 if (ptrType & DW_EH_PE_signed)
558 value = get_unaligned((u16 *) ptr.p16s++);
559 else
560 value = get_unaligned((u16 *) ptr.p16u++);
561 break;
562 case DW_EH_PE_data4:
563#ifdef CONFIG_64BIT
564 if (end < (const void *)(ptr.p32u + 1))
565 return 0;
566 if (ptrType & DW_EH_PE_signed)
567 value = get_unaligned(ptr.p32s++);
568 else
569 value = get_unaligned(ptr.p32u++);
570 break;
571 case DW_EH_PE_data8:
572 BUILD_BUG_ON(sizeof(u64) != sizeof(value));
573#else
574 BUILD_BUG_ON(sizeof(u32) != sizeof(value));
575#endif
576 fallthrough;
577 case DW_EH_PE_native:
578 if (end < (const void *)(ptr.pul + 1))
579 return 0;
580 value = get_unaligned((unsigned long *)ptr.pul++);
581 break;
582 case DW_EH_PE_leb128:
583 BUILD_BUG_ON(sizeof(uleb128_t) > sizeof(value));
584 value = ptrType & DW_EH_PE_signed ? get_sleb128(&ptr.p8, end)
585 : get_uleb128(&ptr.p8, end);
586 if ((const void *)ptr.p8 > end)
587 return 0;
588 break;
589 default:
590 return 0;
591 }
592 switch (ptrType & DW_EH_PE_ADJUST) {
593 case DW_EH_PE_abs:
594 break;
595 case DW_EH_PE_pcrel:
596 value += (unsigned long)*pLoc;
597 break;
598 default:
599 return 0;
600 }
601 if ((ptrType & DW_EH_PE_indirect)
602 && __get_user(value, (unsigned long __user *)value))
603 return 0;
604 *pLoc = ptr.p8;
605
606 return value;
607}
608
609static signed fde_pointer_type(const u32 *cie)
610{
611 const u8 *ptr = (const u8 *)(cie + 2);
612 unsigned int version = *ptr;
613
614 if (*++ptr) {
615 const char *aug;
616 const u8 *end = (const u8 *)(cie + 1) + *cie;
617 uleb128_t len;
618
619
620 if (*ptr != 'z')
621 return -1;
622
623
624 aug = (const void *)ptr;
625 ptr = memchr(aug, 0, end - ptr);
626 if (ptr == NULL)
627 return -1;
628
629 ++ptr;
630 get_uleb128(&ptr, end);
631 get_sleb128(&ptr, end);
632
633 version <= 1 ? (void) ++ptr : (void)get_uleb128(&ptr, end);
634 len = get_uleb128(&ptr, end);
635
636 if (ptr + len < ptr || ptr + len > end)
637 return -1;
638
639 end = ptr + len;
640 while (*++aug) {
641 if (ptr >= end)
642 return -1;
643 switch (*aug) {
644 case 'L':
645 ++ptr;
646 break;
647 case 'P':{
648 signed ptrType = *ptr++;
649
650 if (!read_pointer(&ptr, end, ptrType)
651 || ptr > end)
652 return -1;
653 }
654 break;
655 case 'R':
656 return *ptr;
657 default:
658 return -1;
659 }
660 }
661 }
662 return DW_EH_PE_native | DW_EH_PE_abs;
663}
664
665static int advance_loc(unsigned long delta, struct unwind_state *state)
666{
667 state->loc += delta * state->codeAlign;
668
669
670
671
672 unw_debug("delta %3lu => loc 0x%lx: ", delta, state->loc);
673 return 1;
674}
675
676static void set_rule(uleb128_t reg, enum item_location where, uleb128_t value,
677 struct unwind_state *state)
678{
679 if (reg < ARRAY_SIZE(state->regs)) {
680 state->regs[reg].where = where;
681 state->regs[reg].value = value;
682
683#ifdef UNWIND_DEBUG
684 unw_debug("r%lu: ", reg);
685 switch (where) {
686 case Nowhere:
687 unw_debug("s ");
688 break;
689 case Memory:
690 unw_debug("c(%lu) ", value);
691 break;
692 case Register:
693 unw_debug("r(%lu) ", value);
694 break;
695 case Value:
696 unw_debug("v(%lu) ", value);
697 break;
698 default:
699 break;
700 }
701#endif
702 }
703}
704
705static int processCFI(const u8 *start, const u8 *end, unsigned long targetLoc,
706 signed ptrType, struct unwind_state *state)
707{
708 union {
709 const u8 *p8;
710 const u16 *p16;
711 const u32 *p32;
712 } ptr;
713 int result = 1;
714 u8 opcode;
715
716 if (start != state->cieStart) {
717 state->loc = state->org;
718 result =
719 processCFI(state->cieStart, state->cieEnd, 0, ptrType,
720 state);
721 if (targetLoc == 0 && state->label == NULL)
722 return result;
723 }
724 for (ptr.p8 = start; result && ptr.p8 < end;) {
725 switch (*ptr.p8 >> 6) {
726 uleb128_t value;
727
728 case 0:
729 opcode = *ptr.p8++;
730
731 switch (opcode) {
732 case DW_CFA_nop:
733 unw_debug("cfa nop ");
734 break;
735 case DW_CFA_set_loc:
736 state->loc = read_pointer(&ptr.p8, end,
737 ptrType);
738 if (state->loc == 0)
739 result = 0;
740 unw_debug("cfa_set_loc: 0x%lx ", state->loc);
741 break;
742 case DW_CFA_advance_loc1:
743 unw_debug("\ncfa advance loc1:");
744 result = ptr.p8 < end
745 && advance_loc(*ptr.p8++, state);
746 break;
747 case DW_CFA_advance_loc2:
748 value = *ptr.p8++;
749 value += *ptr.p8++ << 8;
750 unw_debug("\ncfa advance loc2:");
751 result = ptr.p8 <= end + 2
752
753 && advance_loc(value, state);
754 break;
755 case DW_CFA_advance_loc4:
756 unw_debug("\ncfa advance loc4:");
757 result = ptr.p8 <= end + 4
758 && advance_loc(*ptr.p32++, state);
759 break;
760 case DW_CFA_offset_extended:
761 value = get_uleb128(&ptr.p8, end);
762 unw_debug("cfa_offset_extended: ");
763 set_rule(value, Memory,
764 get_uleb128(&ptr.p8, end), state);
765 break;
766 case DW_CFA_val_offset:
767 value = get_uleb128(&ptr.p8, end);
768 set_rule(value, Value,
769 get_uleb128(&ptr.p8, end), state);
770 break;
771 case DW_CFA_offset_extended_sf:
772 value = get_uleb128(&ptr.p8, end);
773 set_rule(value, Memory,
774 get_sleb128(&ptr.p8, end), state);
775 break;
776 case DW_CFA_val_offset_sf:
777 value = get_uleb128(&ptr.p8, end);
778 set_rule(value, Value,
779 get_sleb128(&ptr.p8, end), state);
780 break;
781 case DW_CFA_restore_extended:
782 unw_debug("cfa_restore_extended: ");
783 case DW_CFA_undefined:
784 unw_debug("cfa_undefined: ");
785 case DW_CFA_same_value:
786 unw_debug("cfa_same_value: ");
787 set_rule(get_uleb128(&ptr.p8, end), Nowhere, 0,
788 state);
789 break;
790 case DW_CFA_register:
791 unw_debug("cfa_register: ");
792 value = get_uleb128(&ptr.p8, end);
793 set_rule(value,
794 Register,
795 get_uleb128(&ptr.p8, end), state);
796 break;
797 case DW_CFA_remember_state:
798 unw_debug("cfa_remember_state: ");
799 if (ptr.p8 == state->label) {
800 state->label = NULL;
801 return 1;
802 }
803 if (state->stackDepth >= MAX_STACK_DEPTH)
804 return 0;
805 state->stack[state->stackDepth++] = ptr.p8;
806 break;
807 case DW_CFA_restore_state:
808 unw_debug("cfa_restore_state: ");
809 if (state->stackDepth) {
810 const uleb128_t loc = state->loc;
811 const u8 *label = state->label;
812
813 state->label =
814 state->stack[state->stackDepth - 1];
815 memcpy(&state->cfa, &badCFA,
816 sizeof(state->cfa));
817 memset(state->regs, 0,
818 sizeof(state->regs));
819 state->stackDepth = 0;
820 result =
821 processCFI(start, end, 0, ptrType,
822 state);
823 state->loc = loc;
824 state->label = label;
825 } else
826 return 0;
827 break;
828 case DW_CFA_def_cfa:
829 state->cfa.reg = get_uleb128(&ptr.p8, end);
830 unw_debug("cfa_def_cfa: r%lu ", state->cfa.reg);
831 fallthrough;
832 case DW_CFA_def_cfa_offset:
833 state->cfa.offs = get_uleb128(&ptr.p8, end);
834 unw_debug("cfa_def_cfa_offset: 0x%lx ",
835 state->cfa.offs);
836 break;
837 case DW_CFA_def_cfa_sf:
838 state->cfa.reg = get_uleb128(&ptr.p8, end);
839 fallthrough;
840 case DW_CFA_def_cfa_offset_sf:
841 state->cfa.offs = get_sleb128(&ptr.p8, end)
842 * state->dataAlign;
843 break;
844 case DW_CFA_def_cfa_register:
845 unw_debug("cfa_def_cfa_register: ");
846 state->cfa.reg = get_uleb128(&ptr.p8, end);
847 break;
848
849
850
851 case DW_CFA_GNU_args_size:
852 get_uleb128(&ptr.p8, end);
853 break;
854 case DW_CFA_GNU_negative_offset_extended:
855 value = get_uleb128(&ptr.p8, end);
856 set_rule(value,
857 Memory,
858 (uleb128_t) 0 - get_uleb128(&ptr.p8,
859 end),
860 state);
861 break;
862 case DW_CFA_GNU_window_save:
863 default:
864 unw_debug("UNKNOWN OPCODE 0x%x\n", opcode);
865 result = 0;
866 break;
867 }
868 break;
869 case 1:
870 unw_debug("\ncfa_adv_loc: ");
871 result = advance_loc(*ptr.p8++ & 0x3f, state);
872 break;
873 case 2:
874 unw_debug("cfa_offset: ");
875 value = *ptr.p8++ & 0x3f;
876 set_rule(value, Memory, get_uleb128(&ptr.p8, end),
877 state);
878 break;
879 case 3:
880 unw_debug("cfa_restore: ");
881 set_rule(*ptr.p8++ & 0x3f, Nowhere, 0, state);
882 break;
883 }
884
885 if (ptr.p8 > end)
886 result = 0;
887 if (result && targetLoc != 0 && targetLoc < state->loc)
888 return 1;
889 }
890
891 return result && ptr.p8 == end && (targetLoc == 0 || (
892
893
894
895 state->label == NULL));
896}
897
898
899
900int arc_unwind(struct unwind_frame_info *frame)
901{
902#define FRAME_REG(r, t) (((t *)frame)[reg_info[r].offs])
903 const u32 *fde = NULL, *cie = NULL;
904 const u8 *ptr = NULL, *end = NULL;
905 unsigned long pc = UNW_PC(frame) - frame->call_frame;
906 unsigned long startLoc = 0, endLoc = 0, cfa;
907 unsigned int i;
908 signed ptrType = -1;
909 uleb128_t retAddrReg = 0;
910 const struct unwind_table *table;
911 struct unwind_state state;
912 unsigned long *fptr;
913 unsigned long addr;
914
915 unw_debug("\n\nUNWIND FRAME:\n");
916 unw_debug("PC: 0x%lx BLINK: 0x%lx, SP: 0x%lx, FP: 0x%x\n",
917 UNW_PC(frame), UNW_BLINK(frame), UNW_SP(frame),
918 UNW_FP(frame));
919
920 if (UNW_PC(frame) == 0)
921 return -EINVAL;
922
923#ifdef UNWIND_DEBUG
924 {
925 unsigned long *sptr = (unsigned long *)UNW_SP(frame);
926 unw_debug("\nStack Dump:\n");
927 for (i = 0; i < 20; i++, sptr++)
928 unw_debug("0x%p: 0x%lx\n", sptr, *sptr);
929 unw_debug("\n");
930 }
931#endif
932
933 table = find_table(pc);
934 if (table != NULL
935 && !(table->size & (sizeof(*fde) - 1))) {
936 const u8 *hdr = table->header;
937 unsigned long tableSize;
938
939 smp_rmb();
940 if (hdr && hdr[0] == 1) {
941 switch (hdr[3] & DW_EH_PE_FORM) {
942 case DW_EH_PE_native:
943 tableSize = sizeof(unsigned long);
944 break;
945 case DW_EH_PE_data2:
946 tableSize = 2;
947 break;
948 case DW_EH_PE_data4:
949 tableSize = 4;
950 break;
951 case DW_EH_PE_data8:
952 tableSize = 8;
953 break;
954 default:
955 tableSize = 0;
956 break;
957 }
958 ptr = hdr + 4;
959 end = hdr + table->hdrsz;
960 if (tableSize && read_pointer(&ptr, end, hdr[1])
961 == (unsigned long)table->address
962 && (i = read_pointer(&ptr, end, hdr[2])) > 0
963 && i == (end - ptr) / (2 * tableSize)
964 && !((end - ptr) % (2 * tableSize))) {
965 do {
966 const u8 *cur =
967 ptr + (i / 2) * (2 * tableSize);
968
969 startLoc = read_pointer(&cur,
970 cur + tableSize,
971 hdr[3]);
972 if (pc < startLoc)
973 i /= 2;
974 else {
975 ptr = cur - tableSize;
976 i = (i + 1) / 2;
977 }
978 } while (startLoc && i > 1);
979 if (i == 1
980 && (startLoc = read_pointer(&ptr,
981 ptr + tableSize,
982 hdr[3])) != 0
983 && pc >= startLoc)
984 fde = (void *)read_pointer(&ptr,
985 ptr +
986 tableSize,
987 hdr[3]);
988 }
989 }
990
991 if (fde != NULL) {
992 cie = cie_for_fde(fde, table);
993 ptr = (const u8 *)(fde + 2);
994 if (cie != NULL
995 && cie != &bad_cie
996 && cie != ¬_fde
997 && (ptrType = fde_pointer_type(cie)) >= 0
998 && read_pointer(&ptr,
999 (const u8 *)(fde + 1) + *fde,
1000 ptrType) == startLoc) {
1001 if (!(ptrType & DW_EH_PE_indirect))
1002 ptrType &=
1003 DW_EH_PE_FORM | DW_EH_PE_signed;
1004 endLoc =
1005 startLoc + read_pointer(&ptr,
1006 (const u8 *)(fde +
1007 1) +
1008 *fde, ptrType);
1009 if (pc >= endLoc) {
1010 fde = NULL;
1011 cie = NULL;
1012 }
1013 } else {
1014 fde = NULL;
1015 cie = NULL;
1016 }
1017 }
1018 }
1019 if (cie != NULL) {
1020 memset(&state, 0, sizeof(state));
1021 state.cieEnd = ptr;
1022 ptr = (const u8 *)(cie + 2);
1023 end = (const u8 *)(cie + 1) + *cie;
1024 frame->call_frame = 1;
1025 if (*++ptr) {
1026
1027 if (*ptr == 'z') {
1028 while (++ptr < end && *ptr) {
1029 switch (*ptr) {
1030
1031
1032 case 'L':
1033 case 'P':
1034 case 'R':
1035 continue;
1036 case 'S':
1037 frame->call_frame = 0;
1038 continue;
1039 default:
1040 break;
1041 }
1042 break;
1043 }
1044 }
1045 if (ptr >= end || *ptr)
1046 cie = NULL;
1047 }
1048 ++ptr;
1049 }
1050 if (cie != NULL) {
1051
1052 state.codeAlign = get_uleb128(&ptr, end);
1053
1054 state.dataAlign = get_sleb128(&ptr, end);
1055 if (state.codeAlign == 0 || state.dataAlign == 0 || ptr >= end)
1056 cie = NULL;
1057 else {
1058 retAddrReg =
1059 state.version <= 1 ? *ptr++ : get_uleb128(&ptr,
1060 end);
1061 unw_debug("CIE Frame Info:\n");
1062 unw_debug("return Address register 0x%lx\n",
1063 retAddrReg);
1064 unw_debug("data Align: %ld\n", state.dataAlign);
1065 unw_debug("code Align: %lu\n", state.codeAlign);
1066
1067 if (((const char *)(cie + 2))[1] == 'z') {
1068 uleb128_t augSize = get_uleb128(&ptr, end);
1069
1070 ptr += augSize;
1071 }
1072 if (ptr > end || retAddrReg >= ARRAY_SIZE(reg_info)
1073 || REG_INVALID(retAddrReg)
1074 || reg_info[retAddrReg].width !=
1075 sizeof(unsigned long))
1076 cie = NULL;
1077 }
1078 }
1079 if (cie != NULL) {
1080 state.cieStart = ptr;
1081 ptr = state.cieEnd;
1082 state.cieEnd = end;
1083 end = (const u8 *)(fde + 1) + *fde;
1084
1085 if (((const char *)(cie + 2))[1] == 'z') {
1086 uleb128_t augSize = get_uleb128(&ptr, end);
1087
1088 if ((ptr += augSize) > end)
1089 fde = NULL;
1090 }
1091 }
1092 if (cie == NULL || fde == NULL) {
1093#ifdef CONFIG_FRAME_POINTER
1094 unsigned long top, bottom;
1095
1096 top = STACK_TOP_UNW(frame->task);
1097 bottom = STACK_BOTTOM_UNW(frame->task);
1098#if FRAME_RETADDR_OFFSET < 0
1099 if (UNW_SP(frame) < top && UNW_FP(frame) <= UNW_SP(frame)
1100 && bottom < UNW_FP(frame)
1101#else
1102 if (UNW_SP(frame) > top && UNW_FP(frame) >= UNW_SP(frame)
1103 && bottom > UNW_FP(frame)
1104#endif
1105 && !((UNW_SP(frame) | UNW_FP(frame))
1106 & (sizeof(unsigned long) - 1))) {
1107 unsigned long link;
1108
1109 if (!__get_user(link, (unsigned long *)
1110 (UNW_FP(frame) + FRAME_LINK_OFFSET))
1111#if FRAME_RETADDR_OFFSET < 0
1112 && link > bottom && link < UNW_FP(frame)
1113#else
1114 && link > UNW_FP(frame) && link < bottom
1115#endif
1116 && !(link & (sizeof(link) - 1))
1117 && !__get_user(UNW_PC(frame),
1118 (unsigned long *)(UNW_FP(frame)
1119 + FRAME_RETADDR_OFFSET)))
1120 {
1121 UNW_SP(frame) =
1122 UNW_FP(frame) + FRAME_RETADDR_OFFSET
1123#if FRAME_RETADDR_OFFSET < 0
1124 -
1125#else
1126 +
1127#endif
1128 sizeof(UNW_PC(frame));
1129 UNW_FP(frame) = link;
1130 return 0;
1131 }
1132 }
1133#endif
1134 return -ENXIO;
1135 }
1136 state.org = startLoc;
1137 memcpy(&state.cfa, &badCFA, sizeof(state.cfa));
1138
1139 unw_debug("\nProcess instructions\n");
1140
1141
1142
1143
1144
1145
1146 if (!processCFI(ptr, end, pc, ptrType, &state)
1147 || state.loc > endLoc
1148
1149 || state.cfa.reg >= ARRAY_SIZE(reg_info)
1150 || reg_info[state.cfa.reg].width != sizeof(unsigned long)
1151 || state.cfa.offs % sizeof(unsigned long))
1152 return -EIO;
1153
1154#ifdef UNWIND_DEBUG
1155 unw_debug("\n");
1156
1157 unw_debug("\nRegister State Based on the rules parsed from FDE:\n");
1158 for (i = 0; i < ARRAY_SIZE(state.regs); ++i) {
1159
1160 if (REG_INVALID(i))
1161 continue;
1162
1163 switch (state.regs[i].where) {
1164 case Nowhere:
1165 break;
1166 case Memory:
1167 unw_debug(" r%d: c(%lu),", i, state.regs[i].value);
1168 break;
1169 case Register:
1170 unw_debug(" r%d: r(%lu),", i, state.regs[i].value);
1171 break;
1172 case Value:
1173 unw_debug(" r%d: v(%lu),", i, state.regs[i].value);
1174 break;
1175 }
1176 }
1177
1178 unw_debug("\n");
1179#endif
1180
1181
1182 if (frame->call_frame
1183 && !UNW_DEFAULT_RA(state.regs[retAddrReg], state.dataAlign))
1184 frame->call_frame = 0;
1185 cfa = FRAME_REG(state.cfa.reg, unsigned long) + state.cfa.offs;
1186 startLoc = min_t(unsigned long, UNW_SP(frame), cfa);
1187 endLoc = max_t(unsigned long, UNW_SP(frame), cfa);
1188 if (STACK_LIMIT(startLoc) != STACK_LIMIT(endLoc)) {
1189 startLoc = min(STACK_LIMIT(cfa), cfa);
1190 endLoc = max(STACK_LIMIT(cfa), cfa);
1191 }
1192
1193 unw_debug("\nCFA reg: 0x%lx, offset: 0x%lx => 0x%lx\n",
1194 state.cfa.reg, state.cfa.offs, cfa);
1195
1196 for (i = 0; i < ARRAY_SIZE(state.regs); ++i) {
1197 if (REG_INVALID(i)) {
1198 if (state.regs[i].where == Nowhere)
1199 continue;
1200 return -EIO;
1201 }
1202 switch (state.regs[i].where) {
1203 default:
1204 break;
1205 case Register:
1206 if (state.regs[i].value >= ARRAY_SIZE(reg_info)
1207 || REG_INVALID(state.regs[i].value)
1208 || reg_info[i].width >
1209 reg_info[state.regs[i].value].width)
1210 return -EIO;
1211 switch (reg_info[state.regs[i].value].width) {
1212 case sizeof(u8):
1213 state.regs[i].value =
1214 FRAME_REG(state.regs[i].value, const u8);
1215 break;
1216 case sizeof(u16):
1217 state.regs[i].value =
1218 FRAME_REG(state.regs[i].value, const u16);
1219 break;
1220 case sizeof(u32):
1221 state.regs[i].value =
1222 FRAME_REG(state.regs[i].value, const u32);
1223 break;
1224#ifdef CONFIG_64BIT
1225 case sizeof(u64):
1226 state.regs[i].value =
1227 FRAME_REG(state.regs[i].value, const u64);
1228 break;
1229#endif
1230 default:
1231 return -EIO;
1232 }
1233 break;
1234 }
1235 }
1236
1237 unw_debug("\nRegister state after evaluation with realtime Stack:\n");
1238 fptr = (unsigned long *)(&frame->regs);
1239 for (i = 0; i < ARRAY_SIZE(state.regs); ++i, fptr++) {
1240
1241 if (REG_INVALID(i))
1242 continue;
1243 switch (state.regs[i].where) {
1244 case Nowhere:
1245 if (reg_info[i].width != sizeof(UNW_SP(frame))
1246 || &FRAME_REG(i, __typeof__(UNW_SP(frame)))
1247 != &UNW_SP(frame))
1248 continue;
1249 UNW_SP(frame) = cfa;
1250 break;
1251 case Register:
1252 switch (reg_info[i].width) {
1253 case sizeof(u8):
1254 FRAME_REG(i, u8) = state.regs[i].value;
1255 break;
1256 case sizeof(u16):
1257 FRAME_REG(i, u16) = state.regs[i].value;
1258 break;
1259 case sizeof(u32):
1260 FRAME_REG(i, u32) = state.regs[i].value;
1261 break;
1262#ifdef CONFIG_64BIT
1263 case sizeof(u64):
1264 FRAME_REG(i, u64) = state.regs[i].value;
1265 break;
1266#endif
1267 default:
1268 return -EIO;
1269 }
1270 break;
1271 case Value:
1272 if (reg_info[i].width != sizeof(unsigned long))
1273 return -EIO;
1274 FRAME_REG(i, unsigned long) = cfa + state.regs[i].value
1275 * state.dataAlign;
1276 break;
1277 case Memory:
1278 addr = cfa + state.regs[i].value * state.dataAlign;
1279
1280 if ((state.regs[i].value * state.dataAlign)
1281 % sizeof(unsigned long)
1282 || addr < startLoc
1283 || addr + sizeof(unsigned long) < addr
1284 || addr + sizeof(unsigned long) > endLoc)
1285 return -EIO;
1286
1287 switch (reg_info[i].width) {
1288 case sizeof(u8):
1289 __get_user(FRAME_REG(i, u8),
1290 (u8 __user *)addr);
1291 break;
1292 case sizeof(u16):
1293 __get_user(FRAME_REG(i, u16),
1294 (u16 __user *)addr);
1295 break;
1296 case sizeof(u32):
1297 __get_user(FRAME_REG(i, u32),
1298 (u32 __user *)addr);
1299 break;
1300#ifdef CONFIG_64BIT
1301 case sizeof(u64):
1302 __get_user(FRAME_REG(i, u64),
1303 (u64 __user *)addr);
1304 break;
1305#endif
1306 default:
1307 return -EIO;
1308 }
1309
1310 break;
1311 }
1312 unw_debug("r%d: 0x%lx ", i, *fptr);
1313 }
1314
1315 return 0;
1316#undef FRAME_REG
1317}
1318EXPORT_SYMBOL(arc_unwind);
1319